Support for replicating tokens on chain

[gkaracha]

Closes #263.

• Implement a mock cfmm oracle to use in tests. To ensure that our tests can catch forgotten changes (i.e., avoid mixing it up with the usual mock oracle), the name of the price entrypoint is %getCfmmPrice (as opposed to %getPrice which is the one we use for the mock oracle). This is not very descriptive and does not indicate the units we expect the fraction to have (tok/ctok), but it's only a placeholder for now. We might want to change this in the future, or even perhaps get it from the yaml file at build time. Also: currently both mock oracles (index and cfmm) have an update entrypoint but since this is not part of Checker's spec I saw no good reason to deviate on the name of this one too.
• Extend the yaml specification with another field (tracking_type) which can take one of two values: index or token.
• Generalize the type of the (index-)oracle to a pair of nats (CHF in TEZ, (TEZ/CHF)). This reduces the number of differences between token-based and index-based instances quite some.
• Turn the calculation of the target into jinja templates. The different price calculation does manifest itself in the drift adjustment (see https://github.com/tezos-checker/checker/issues/263#issuecomment-969045606), but indirectly, through the target. Hence the target became a jinja template and not the drift derivative.
• Add docs/prices.md with some notes about price calculations, taken from https://github.com/tezos-checker/checker/issues/263#issuecomment-969045606.
• Extend CI to run all the tests with all the three possible configurations: checker-index-tez.yaml, checker-index-fa2.yaml, and checker-token-fa2.yaml.

[github-actions[bot]]

Gas costs: No change.	Entrypoint sizes	e74532c074c71b86d520f229940c97b76815b6e3	070415535592f7002ad75e489714337f493c03f1	Diff
touch	56697	56504	-193

Test coverage	e74532c074c71b86d520f229940c97b76815b6e3	070415535592f7002ad75e489714337f493c03f1	Diff
oraclePriceType.ml	None	78.57	78.57
price.ml	76.92	100	23.08
checkerTypes.ml	77.78	78.57	0.789999999999992
checker.ml	94.97	95.34	0.37000000000000455
TOTAL	81.86	81.91	0.04999999999999716

[github-actions[bot]]

Gas costs	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	c13a9d357dd4d8e6395ebb6ff0834e3a5a79b76b	Diff
checker%touch	42390	42430	40
checker%create_burrow	22343	22344	1
checker%transfer	6311	6312	1
checker%add_liquidity	12599	12600	1
checker%touch_burrow	6102	6103	1
checker%burn_kit	7359	7360	1
checker%mint_kit	7131	7132	1
checker%set_burrow_delegate	18365	18366	1

Entrypoint sizes	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	c13a9d357dd4d8e6395ebb6ff0834e3a5a79b76b	Diff
touch	56504	56880	376
receive_price	287	289	2

Test coverage	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	c13a9d357dd4d8e6395ebb6ff0834e3a5a79b76b	Diff
targetCalculation.ml	None	100	100
getOracleEntrypoint.ml	None	75	75
price.ml	100	76.92	-23.08
checkerTypes.ml	77.78	78.57	0.789999999999992
checker.ml	94.97	94.98	0.010000000000005116
TOTAL	81.9	81.88	-0.020000000000010232

[github-actions[bot]]

Gas costs	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	6662564661e76ec7dfdd215d92f0ec427c9730bd	Diff
checker%touch	42390	42430	40
checker%create_burrow	22343	22344	1
checker%add_liquidity	12599	12600	1
checker%set_burrow_delegate	18365	18366	1
checker%mint_kit	7131	7132	1
checker%touch_burrow	6102	6103	1
checker%transfer	6311	6312	1
checker%burn_kit	7359	7360	1

Entrypoint sizes	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	6662564661e76ec7dfdd215d92f0ec427c9730bd	Diff
touch	56504	56687	183
receive_price	287	289	2

Test coverage	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	6662564661e76ec7dfdd215d92f0ec427c9730bd	Diff
targetCalculation.ml	None	100	100
getOracleEntrypoint.ml	None	75	75
checkerTypes.ml	77.78	78.57	0.789999999999992
checker.ml	94.97	94.98	0.010000000000005116
TOTAL	81.9	81.91	0.009999999999990905

[gkaracha]

OK, I think this one is finally ready for review @dorranh! The description is also now up to date.

After merging this I think we'll be at the point where the README should have separate build/deployment/testing instructions per configuration. Hopefully the API won't really change after this PR so we can start looking at #118 soon after.

I had to deactivate three tests that are configuration-specific for CI to pass, but we should be able to renable those tests once #284 is addressed (partially or completely; I might be able to fix that rather easily, being on the OCaml side). Either way, I'd go ahead and merge this PR without them for now.

[github-actions[bot]]

Gas costs	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	a9d6a8824a3983eeeccce8e4809755d2cfdbee9b	Diff
checker%touch	42390	42430	40
checker%touch_burrow	6102	6103	1
checker%add_liquidity	12599	12600	1
checker%mint_kit	7131	7132	1
checker%transfer	6311	6312	1
checker%set_burrow_delegate	18365	18366	1
checker%create_burrow	22343	22344	1
checker%burn_kit	7359	7360	1
checker%update_operators	5589	5590	1

Entrypoint sizes	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	a9d6a8824a3983eeeccce8e4809755d2cfdbee9b	Diff
touch	56504	56675	171
receive_price	287	289	2

Test coverage	74f9e3ddf7b033c41faf8ab471aefbf912d455ed	a9d6a8824a3983eeeccce8e4809755d2cfdbee9b	Diff
targetCalculation.ml	None	100	100
getOracleEntrypoint.ml	None	75	75
checkerTypes.ml	77.78	78.57	0.789999999999992
checker.ml	94.97	94.98	0.010000000000005116
TOTAL	81.9	81.89	-0.010000000000005116

[gkaracha]

@dorranh shall I go ahead and merge this?

[dorranh]

@gkaracha, yep I think it's good to go following our separate discussion of the target calculation.