doc: add guidance for RPC to developer notes
Adds guidance statements to the RPC interface section of the developer notes with examples of when to implement -deprecatedrpc=
.
Wanted to increase awareness of preferred RPC implementation approaches for newer contributors.
This implements some of what's discussed in https://github.com/bitcoin/bitcoin/issues/29912#issuecomment-2081678433
Opinions may differ, so please don't be shy. We want to make RPC as solid/safe as possible.
Examples of discussions where guidelines/context might have added value: https://github.com/bitcoin/bitcoin/pull/30212#issuecomment-2347371722 https://github.com/bitcoin/bitcoin/pull/29845#discussion_r1571053657 https://github.com/bitcoin/bitcoin/pull/30381#pullrequestreview-2160865613 https://github.com/bitcoin/bitcoin/pull/29954#issuecomment-2103628952 https://github.com/bitcoin/bitcoin/pull/30410#pullrequestreview-2167870869 https://github.com/bitcoin/bitcoin/pull/30713 https://github.com/bitcoin/bitcoin/pull/30381 https://github.com/bitcoin/bitcoin/pull/29060#pullrequestreview-2406688998