Add a flag to override ribovore filters

[AntonPetrov]

In some cases ribovore produces warnings for some legitimate hits, but since R2DT filters out all ribovore hits with warnings, it is desirable to be able to override this behaviour.

For example, some microRNAs are palindromic which is one of the filters in ribovore. This filter should be turned on by default but for bona fide microRNAs R2DT could be run with a special flag to disable it.

In another example, the web app could automatically rerun R2DT if the default settings produce no diagram because of the ribovore filtering. The UI could say that the diagram should be treated with caution.

In the future, the ribovore filters should be investigated in more detail using the entire RNAcentral dataset to see which sequences trigger which filters.