Remove PortfolioId from OffChain Assets

[HenriqueNogara]

This PR changes how offchain affirmations are handled. Explicit affirmation from both the sender and receiver are no longer required.

changelog

modified API

• Leg has been updated and is now an enum;
• DuplicateReceiptUid, ReceiptInstructionIdMissmatch, MultipleReceiptsForOneLeg and UnexpectedLegStatus error variants have been added for the settlement_pallet;
• FailedToLockTokens, PortfolioMismatch, and OffChainAssetMustBeAffirmedWithReceipts error variants have been removed from the settlement_pallet;
• polymesh_schema.json has been updated with the new leg type;

modified logic

• Only one affirmation is required for an offchain leg;

data migration

• The legs in storage were updated to fit the new type;

[codecov[bot]]

Codecov Report

Merging #1483 (22a49de) into develop (efa610d) will increase coverage by 0.18%. The diff coverage is 75.31%.

@@             Coverage Diff             @@
##           develop    #1483      +/-   ##
===========================================
+ Coverage    54.41%   54.59%   +0.18%     
===========================================
  Files          151      151              
  Lines        32949    33031      +82     
===========================================
+ Hits         17928    18033     +105     
+ Misses       15021    14998      -23     

Impacted Files	Coverage Δ
pallets/common/src/traits/settlement.rs	0.00% <0.00%> (ø)
primitives/src/weight_meter.rs	68.33% <0.00%> (+1.12%)	:arrow_up:
pallets/weights/src/pallet_settlement.rs	52.99% <57.37%> (+0.36%)	:arrow_up:
pallets/settlement/src/lib.rs	79.18% <78.32%> (+1.04%)	:arrow_up:
primitives/src/settlement.rs	80.97% <90.58%> (+7.13%)	:arrow_up:
pallets/sto/src/lib.rs	50.10% <100.00%> (+0.21%)	:arrow_up:

... and 1 file with indirect coverage changes

[adamdossa]

As discussed:

• remove check that OffChain leg does not reference on-chain ticker
• do not un-claim receipt when an instruction fails
• once a OffChain leg has been "affirmed" (via signed data) it should not be possible to "undo" this - i.e. you cannot invalidate any existing receipts used or otherwise. i.e. remove change_receipt_validaty