Cleanup stacks-signer by adding thiserror and documentation

[jferrant]

Changes:
Alphabetically order cargo.toml dependencies
Forbids no documentation
Adds a README to be filled in as the CLI and SDK is expanded.
Addresses a bunch of random clippy warnings.
Uses thiserror to simplify boiler plate code for error definitions/formatting.

• My initial investigations of thiserror show no use of unsafe throughout the code base. Please feel free to audit this crate in case you have concerns about adding it to the stacks-signer lib. If no complaints, I may create some new issues to add it to other sections of the stacks-network repo.

This PR addresses part of #3882

Please add reviewers as you see fit who may have a strong opinion for or against thiserror or the use of a different crate.

[codecov]

Codecov Report

Merging #3883 (439d4fe) into feat/stacks-signer (0bf6285) will increase coverage by 0.00%.
The diff coverage is 0.00%.

@@                 Coverage Diff                 @@
##           feat/stacks-signer    #3883   +/-   ##
===================================================
  Coverage                0.16%    0.16%           
===================================================
  Files                     339      339           
  Lines                  290265   290213   -52     
===================================================
  Hits                      469      469           
+ Misses                 289796   289744   -52     

Files Changed	Coverage Δ
libsigner/src/error.rs	0.00% <0.00%> (ø)
libsigner/src/events.rs	0.00% <ø> (ø)
libsigner/src/runloop.rs	0.00% <ø> (ø)
libsigner/src/session.rs	0.00% <ø> (ø)
libsigner/src/tests/http.rs	0.00% <0.00%> (ø)
libsigner/src/tests/mod.rs	0.00% <0.00%> (ø)

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[xoloki]

LGTM

[jcnelson]

Hey @jferrant, this looks like it's otherwise ready to go, but it has a few merge conflicts. Can you resolve these and merge this PR when you get a moment? Thanks!

[jferrant]

Hey @jferrant, this looks like it's otherwise ready to go, but it has a few merge conflicts. Can you resolve these and merge this PR when you get a moment? Thanks!

Oh completely forgot I had this open . yes will do right now.