fix(semver): improved support of the Python Version Identification part of PEP440

[icj217]

The semver util's current version logic does not fully implement/adhere to PEP440 in two respects:

• There is no support for "local version identifiers", which are basically the same as SemVer's build metadata (e.g. 1.2.3+foobar), when used in conjunction with a pre-release label.
• The current pre-release logic doesn't reflect the ability for python pre-releases to include post-release and developmental release labels in conjunction with the pre-release itself (e.g. 1.2.3.rc1.post2.dev3)

This PR addresses these gaps so that the python release supports these features. I've kept support for the pre label as a synonym for dev.

Projen and JSII's logic diverged ever so slightly re: including a . between the version and pre-release labels (e.g. projen was yielding 1.2.3rc0 while JSII would yield 1.2.3.rc0. I decided to update projen's logic to mirror that from JSII.

E.g. now 1.2.3-rc.1.dev.2.post.3+foobar will now yield 1.2.3.rc1.post3.dev2+foobar for python packages.

I have an identical PR open over in jsii: aws/jsii#4462

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 80.59701% with 13 lines in your changes are missing coverage. Please review.

Project coverage is 96.33%. Comparing base (41a2b73) to head (44559db).
Report is 7 commits behind head on main.

Files	Patch %	Lines
src/util/semver.ts	80.59%	13 Missing ⚠️

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Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3474   +/-   ##
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  Coverage   96.32%   96.33%           
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  Files         191      191           
  Lines       37407    37445   +38     
  Branches     3489     3498    +9     
=======================================
+ Hits        36032    36071   +39     
+ Misses       1375     1374    -1     

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[mrgrain]

@icj217 Thanks for this! I suspect this needs a new release of pacmak with the respective change first?

[mrgrain]

See question

[icj217]

@icj217 Thanks for this! I suspect this needs a new release of pacmak with the respective change first?

@mrgrain Not necessarily. I think this can be merged first because this logic applies to any python package (not just a JSII-based one) that a user registers as a dependency in their project. JSII projects won't be able to publish versions that would exercise the new logic here until the pacmak release is published.