[refactor] one method to fetch corpus and list in CodeSection

Also, added .idea, .parcel-cache to .gitignore
3 jobs for 453-dev-false-occurrence-count-fix in 24 minutes (queued for 5 minutes and 41 seconds)
Status Job ID Name Coverage
  Check Lint
passed #17861
check-lint

00:07:51

 
  Compile
passed #17862
compile

00:08:52

 
  Test
passed #17863
test

00:07:16