chore: factorization and simplification

[ldez]

Adds formatStmts and formatExprs to handle slices of statements or expressions.

Adds formatFile for consistency with other formatXXX methods.

Refactors the algorithm used to stop the rounds into something more human-readable and adds comments to explain the algorithm.
Renames the variable linesToShorten into nbLinesToShorten because the name was ambiguous.

Renames the function tags.HasMultipleTags into tags.HasMultipleEntries because the word Tags is ambiguous in the context.

Still the same goal: ease the maintenance.