fix(app): Stop panicking at startup when parsing the app version - release blocker

[teor2345]

Motivation

Zebra panics in some git/machine environments when running app_version() at startup.

When we changed the version to 1.0.0, this code would always have panicked, because it expected a pre-release version.

I also fixed a similar potential panic in the get_info RPC version code.

Close #6879

Specifications

https://semver.org/#semantic-versioning-specification-semver

For the RPC:
https://github.com/bitcoin/bips/blob/master/bip-0014.mediawiki#proposal

Complex Code or Requirements

The previous code had a bunch of undocumented assumptions. This code is longer but all the assumptions are spelled out, and the expect()s are justified.

Solution

• Re-implement git version parsing, removing most of the panics
• Remove a potential panic in the get_info() RPC

Review

This is an urgent release blocker.

Reviewer Checklist

• Will the PR name make sense to users?
  • Does it need extra CHANGELOG info? (new features, breaking changes, large changes)
• Are the PR labels correct?
• Does the code do what the ticket and PR says?
  • Does it change concurrent code, unsafe code, or consensus rules?
• How do you know it works? Does it have tests?

Follow Up Work

We could add tests for this parsing, but there isn't much point because the remaining panics should be impossible.

[codecov]

Codecov Report

Merging #6888 (5fd4b09) into main (9959a6c) will decrease coverage by 0.16%.
The diff coverage is 32.20%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6888      +/-   ##
==========================================
- Coverage   77.72%   77.56%   -0.16%     
==========================================
  Files         310      310              
  Lines       41416    41475      +59     
==========================================
- Hits        32192    32172      -20     
- Misses       9224     9303      +79