Add command-line option to exclude certain rules

[lionel-nj]

Is your feature request related to a problem? Please describe. PR#188 adds new feature to enable exclusion of files from the validation process. However, once these files are excluded, the execution method of use cases related to said files should not be called.

Describe the solution you'd like It should be possible to map the list of use cases related to a single file and execute the validation process on a subset of use cases

[barbeau]

Given that the v2 architecture is able to run on even the largest GTFS datasets, we no longer have the need to exclude certain files from validation. Therefore, we're changing this issue to generally focus on the ability to exclude certain rules from being executed/output, in case an agency wants to eliminate noisy output that isn't relevant to them.

[emmambd]

#1292 is related to this