This change reorganizes the `tx/transactors` directory for consistency and discoverability. There are no behavioral changes, this is a pure refactor. Underscores were chosen as the way to separate multi-words as this is the more popular option in C++ projects.
Specific changes:
- Rename all subdirectories to lowercase/snake_case (`AMM` → `amm`, `Check` → `check`, `NFT` → `nft`, `PermissionedDomain` → `permissioned_domain`, etc.)
- Merge `AMM/` and `Offer/` into `dex/`, including `PermissionedDEXHelpers`
- Rename `MPT/` → `token/`, absorbing `SetTrust` and `Clawback`
- Move top-level transactors into named groups: `account/`, `bridge/`, `credentials/`, `did/`, `escrow/`, `oracle/`, `payment/`, `payment_channel/`, `system/`
- Update all include paths across the codebase and `transactions.macro`
The existing code added the git commit info (`GIT_COMMIT_HASH` and `GIT_BRANCH`) to every file, which was a problem for leveraging `ccache` to cache build objects. This change adds a separate C++ file from where these compile-time variables are propagated to wherever they are needed. A new CMake file is added to set the commit info if the `git` binary is available.
When `gateway_balances` gets called on an account that is involved in the `EscrowCreate` transaction (with MPT being escrowed), the method returns internal error. This change fixes this case by excluding the MPT type when totaling escrow amount.
The `Subscribe` tests were flaky, because each test performs some operations (e.g. sends transactions) and waits for messages to appear in subscription with a 100ms timeout. If tests are slow (e.g. compiled in debug mode or a slow machine) then some of them could fail. This change adds an attempt to synchronize the background Env's thread and the test's thread by ensuring that all the scheduled operations are started before the test's thread starts to wait for a websocket message. This is done by limiting I/O threads of the app inside Env to 1 and adding a synchronization barrier after closing the ledger.
