Support metric with a restriction on some files/directory to be skipped

[morucci]

For instance one would we like to skip a directory that should not be handled as code, like upstream patched in rpm packaging or dependencies modules in js.

Then the line modified amount will not reflect the changes on those paths.

To do so:

• Support for added/removed by file details in the DB and return values in the commit endpoint
• Improve the query builder to support by files/directories restrictions
• Improve the search queries to handle excluded paths in line count amount