feat: add `simulate` RPC to dry-run a tx (XLS-69d)

[mvadari]

High Level Overview of Change

This PR adds a new API method, titled simulate, which executes a dry run of a transaction submission.

This PR also fixes #5070.

Context of Change

It is useful to take a transaction, simulate execution it in the current ledger, and return the metadata - but not persist the transaction in the ledger. This can be used for testing, analysis, and more.

XLS spec: https://github.com/XRPLF/XRPL-Standards/pull/207

Type of Change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Refactor (non-breaking change that only restructures code)
• [ ] Performance (increase or change in throughput and/or latency)
• [x] Tests (you added tests for code that already exists, or your new feature included in this PR)
• [ ] Documentation update
• [ ] Chore (no impact to binary, e.g. .gitignore, formatting, dropping support for older tooling)
• [ ] Release

API Impact

• [x] Public API: New feature (new methods and/or new fields)
• [ ] Public API: Breaking change (in general, breaking changes should only impact the next api_version)
• [ ] libxrpl change (any change that may affect libxrpl or dependents of libxrpl)
• [ ] Peer protocol change (must be backward compatible or bump the peer protocol version)

Test Plan

Testing is still in progress. Unit tests are and will be added.

Current Status

This PR is complete and ready for review. You can build this branch and sync with the network of your choice (including Mainnet). The public is welcome to test and use this code (at your own risk). Next steps are code review and QA testing.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 98.21429% with 6 lines in your changes missing coverage. Please review.

Project coverage is 78.1%. Comparing base (50b8f19) to head (4845f7b). Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
src/xrpld/rpc/detail/TransactionSign.cpp	94.0%	5 Missing :warning:
src/xrpld/app/tx/detail/apply.cpp	90.0%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #5069     +/-   ##
=========================================
+ Coverage     78.0%   78.1%   +0.1%     
=========================================
  Files          789     790      +1     
  Lines        67061   67279    +218     
  Branches      8108    8101      -7     
=========================================
+ Hits         52324   52562    +238     
+ Misses       14737   14717     -20     

Files with missing lines	Coverage Δ
include/xrpl/protocol/ErrorCodes.h	100.0% <ø> (ø)
src/libxrpl/protocol/ErrorCodes.cpp	85.7% <ø> (ø)
src/libxrpl/protocol/InnerObjectFormats.cpp	100.0% <100.0%> (ø)
src/xrpld/app/ledger/detail/BuildLedger.cpp	91.4% <100.0%> (ø)
src/xrpld/app/ledger/detail/LedgerMaster.cpp	44.0% <100.0%> (+0.1%)	:arrow_up:
src/xrpld/app/ledger/detail/OpenLedger.cpp	73.4% <100.0%> (+0.3%)	:arrow_up:
src/xrpld/app/main/Main.cpp	79.8% <ø> (ø)
src/xrpld/app/misc/NetworkOPs.cpp	70.1% <100.0%> (+<0.1%)	:arrow_up:
src/xrpld/app/misc/TxQ.h	98.2% <ø> (ø)
src/xrpld/app/misc/detail/TxQ.cpp	98.8% <100.0%> (+<0.1%)	:arrow_up:
... and 18 more

... and 4 files with indirect coverage changes

[mvadari]

This is now fully finished and ready for review.

[oleks-rip]

Maybe you forgot to commit but I don't see expired NFT offer tests

[mvadari]

Maybe you forgot to commit but I don't see expired NFT offer tests

#5247

[Vjkhannaripple]

Adding the performance testing results composed by @sophiax851 here for reference. Conclusion:

A rippled client handler node can support ~1200 requests/sec of Simulate RPC load, simulating mixed payment transaction loads (considered the heaviest type of Simulate), while in an XRPL network with real payment transactions load (150tps). It far exceeds the RPC limit (~100 requests/sec) allowed for a single IP that is not on the rippled whitelist. In other words, a rippled node can handle the maximum Simulate traffic permitted from multiple (>10) anonymous sources

Compared to the TX RPC load, the type of Simulate RPC used in the testing is 2.2 times more CPU resource-intensive.

Based on the above results, the risk of using Simulate as a tool to overload a rippled node appears to be low and is outweighed by the benefits Simulate is designed to provide to the community users, therefore, it passes performance testing.

[Bronek]

This PR increases overall test coverage of the project by 0.10% , to 78.10% , which is really nice - thank you @mvadari !