The codebase is filled with includes that are unused, and which thus can be removed. At the same time, the files often do not include all headers that contain the definitions used in those files. This change uses clang-format and clang-tidy to clean up the includes, with minor manual intervention to ensure the code compiles on all platforms.
Remove `tx_history` and `ledger_header` methods from API version 2.
Update `RPC::Handler` to allow for methods (or method implementations)
to be API version specific. This partially resolves#4727. We can now
store multiple handlers with the same name, as long as they belong to
different (non-overlapping) API versions. This necessarily impacts the
handler lookup algorithm and its complexity; however, there is no
performance loss on x86_64 architecture, and only minimal performance
loss on arm64 (around 10ns). This design change gives us extra
flexibility evolving the API in the future, including other parts of
#4727.
In API version 2, `tx_history` and `ledger_header` are no longer
recognised; if they are called, `rippled` will return error
`unknownCmd`
Resolve#3638Resolve#3539
