Refactor soroban-simulation to use the e2e_invoke

[dmkozh]

What

Refactor soroban-simulation to use the e2e_invoke and also to be more modular/reusable.

• Use e2e_invoke for invoking host functions in recording mode
• Separate network config and adjustment config into separate structs for easier testing/caching etc.
• Clean up the storage logic to clearly distinguish between snapshots with and without archive access
• Added some documentation for public functions/structs
• Added some basic test coverage. I didn't try to verify the math for every number, but I did sanity-check them. The host function simulation accuracy is mostly covered on e2e_invoke side.
• Reuse host code for common test and non-test utilities

Why

Improving simulation quality, as well as maintainability.

Known limitations

N/A

[2opremio]

@dmkozh Nice! I see that the public API has changed. Did you take into consideration the impact at https://github.com/stellar/soroban-rpc/blob/main/cmd/soroban-rpc/lib/preflight/src/lib.rs and whether it satisfies all the current functionality?

[2opremio]

@dmkozh I would like to make sure that all integration tests of soroban-rpc pass after these changes. Could you take a stab at adapting the rpc code?

[2opremio]

Another option is to do this in a two-step process, keeping an externally-compatible layer at first.

[dmkozh]

Did you take into consideration the impact at https://github.com/stellar/soroban-rpc/blob/main/cmd/soroban-rpc/lib/preflight/src/lib.rs and whether it satisfies all the current functionality?

Of course, these changes are meant to be functionally no-op (besides the additional capabilities, like ledger diffs we've discussed before - but there is no need to use them immediately). I'll definitely help with the migration, but this PR has to be finalized first.