Modularise app/tx

[a1q123456]

High Level Overview of Change

This PR moves transactors and some other dependencies to libxrpl.

This PR is part of the modularisation of the transactors. See all PRs here:
#6222
#6223
#6224
#6225
#6226
#6227
#6228

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• 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)
• 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

• 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)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.3%. Comparing base (0595bec) to head (d6fcb49).

Additional details and impacted files

@@                             Coverage Diff                             @@
##           a1q123456/decouple-app-tx-with-application   #6228    +/-   ##
===========================================================================
  Coverage                                        79.2%   79.3%            
===========================================================================
  Files                                             848     849     +1     
  Lines                                           71736   71875   +139     
  Branches                                         8282    8286     +4     
===========================================================================
+ Hits                                            56841   56978   +137     
- Misses                                          14895   14897     +2     

Files with missing lines	Coverage Δ
include/xrpl/ledger/AmendmentTable.h	100.0% <ø> (ø)
include/xrpl/protocol/Protocol.h	100.0% <ø> (ø)
include/xrpl/protocol/detail/transactions.macro	100.0% <ø> (ø)
include/xrpl/server/LoadFeeTrack.h	90.0% <ø> (ø)
include/xrpl/tx/ApplyContext.h	100.0% <ø> (ø)
include/xrpl/tx/InvariantCheck.h	100.0% <ø> (ø)
include/xrpl/tx/SignerEntries.h	100.0% <ø> (ø)
include/xrpl/tx/Transactor.h	100.0% <ø> (ø)
include/xrpl/tx/applySteps.h	100.0% <ø> (ø)
include/xrpl/tx/paths/BookTip.h	50.0% <ø> (ø)
... and 183 more

... and 1 file with indirect coverage changes

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