refactor: Error handling

[plebhash]

SRI error handling can be improved in a few different ways, this is an umbrella issue tracker

the issues below will require some substantial refactoring effort, so they are not necessarily trivial

roles

• refactor: improve Error handling (clean up unwraps) #736
• refactor: remove generic cases from pool's handle_error #777

protocols

• remove all the TODOs #52
• make sure Error types from protocols crates implement std::error::Error #921

[pavlenex]

@plebhash How about things mentioned in #50? Should we close that one both issues sound similar but context seems a bit different, and this issue is a bit more concrete in defining what needs to be done?

[plebhash]

@plebhash How about things mentioned in #50? Should we close that one both issues sound similar but context seems a bit different, and this issue is a bit more concrete in defining what needs to be done?

#778 was originally written to address Error handling on roles, while #50 is referring to Error handling on low level crates (protocols), so they were originally slightly different things

but I'm editing the description of #778 to include a reference to #52 (which was the only sub-issue that was still open on #50)

and I'm closing #50 so we use this as a tracker instead