Filter semgrep results based on initial findings

[drdavella]

Overview

Only run semgrep on files that have findings from initial run

Description

• This is an optimization designed to make semgrep faster by limiting the number of files it analyzes
  • This is motivated by the fact that semgrep execution is our long pole in certain environments
• Only files that have findings from the initial "discovery" run will be considered for further analysis
• In order to enable this change I made some changes to the structure of processed sarif results

[codecov]

Codecov Report

Merging #115 (552c714) into main (f20e61f) will increase coverage by 0.01%.
The diff coverage is 98.51%.

@@            Coverage Diff             @@
##             main     #115      +/-   ##
==========================================
+ Coverage   95.95%   95.96%   +0.01%     
==========================================
  Files          62       64       +2     
  Lines        2572     2630      +58     
==========================================
+ Hits         2468     2524      +56     
- Misses        104      106       +2     

Files	Coverage Δ
src/codemodder/codemodder.py	97.01% <100.00%> (+0.06%)	⬆️
src/codemodder/codemods/api/__init__.py	95.31% <100.00%> (ø)
src/codemodder/codemods/base_codemod.py	100.00% <100.00%> (ø)
src/codemodder/codemods/base_visitor.py	97.29% <100.00%> (ø)
src/codemodder/executor.py	92.59% <100.00%> (+0.13%)	⬆️
src/codemodder/file_context.py	100.00% <100.00%> (ø)
src/codemodder/result.py	100.00% <100.00%> (ø)
src/codemodder/semgrep.py	94.73% <100.00%> (ø)
src/core_codemods/django_debug_flag_on.py	100.00% <ø> (ø)
.../core_codemods/django_session_cookie_secure_off.py	98.30% <ø> (ø)
... and 4 more

[drdavella]

I want to merge #116 and release a bugfix before merging this one.