fix(process): refactor away the bugs and race conditions in proc_t

[FrogTheFrog]

Description

This is a continuation of #3417.

Moved the code around to remove possible race conditions and bad patterns in general. I tried to not change the logic at all if possible, therefore while some of the sonarqube suggestions are valid, will not be addressed.

Screenshot

Since I have moved stuff around to be in the same order as a header, the diff can be hard to read. These are the screenshots I used for checking for changes (for the "refactoring" commit only):

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Issues Fixed or Closed

Resolves this PR: #3417

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Dependency update (updates to dependencies)
• Documentation update (changes to documentation)
• Repository update (changes to repository files, e.g. .github/...)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the in code docstring/documentation-blocks for new or existing methods/components

[codecov]

Codecov Report

Attention: Patch coverage is 1.48515% with 199 lines in your changes missing coverage. Please review.

Project coverage is 11.59%. Comparing base (23e1314) to head (29ba06f).

Files with missing lines	Patch %	Lines
src/process.cpp	1.57%	130 Missing and 57 partials ⚠️
src/nvhttp.cpp	0.00%	0 Missing and 7 partials ⚠️
src/confighttp.cpp	0.00%	0 Missing and 2 partials ⚠️
src/stream.cpp	0.00%	0 Missing and 2 partials ⚠️
src/process.h	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3604      +/-   ##
==========================================
- Coverage   11.62%   11.59%   -0.04%     
==========================================
  Files          93       93              
  Lines       17318    17344      +26     
  Branches     8091     8114      +23     
==========================================
- Hits         2014     2011       -3     
+ Misses      14710    12827    -1883     
- Partials      594     2506    +1912     

Flag	Coverage Δ
Linux	11.26% <1.53%> (-0.05%)	⬇️
Windows	12.99% <0.00%> (-0.05%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/process.h	0.00% <0.00%> (-12.50%)	⬇️
src/confighttp.cpp	0.00% <0.00%> (ø)
src/stream.cpp	2.51% <0.00%> (ø)
src/nvhttp.cpp	18.62% <0.00%> (+0.08%)	⬆️
src/process.cpp	0.74% <1.57%> (-0.35%)	⬇️

... and 27 files with indirect coverage changes

[sonarqubecloud]

Quality Gate failed

Failed conditions
5 New issues
5 New Code Smells (required ≤ 0)

See analysis details on SonarQube Cloud

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