L1: clean up

Some cleanup in L1:

• development flag: match doublets with mc
• remove obsolete "Sts: prefixes from the algorithm core
• give reasonable names to f* methods like f32() -> findTripletsStage2()

requested review from @s.zharko

assigned to @se.gorbunov

Dear @se.gorbunov, @v.akishina,

you have been identified as code owner of at least one file which was changed with this merge request.

Please check the changes and approve them or request changes.

added CodeOwners label

merged