When launching task arrays, make BoutiquesOutputFilenameRenamer module refuse output names that don't have patterns

[prioux]

The BoutiquesOutputFilenameRenamer allow users to provide special patterns to name their outputs automatically based on their inputs.

Currently, when launching task arrays, if the user sets an output name that is constant and doesn't include any pattern, all the tasks will create outputs with the same names, crushing each other's output file on the destination data provider.

The module should detect such a situation in the after_form() callback and let the user know it's not correct, and allow them to reenter a proper output name pattern.

[MontrealSergiy]

I thought CBRAIN is supposed to add some suffix if output folder already exists

[prioux]

Only when the task is not using that renaming module. The renaming module doesn't add the suffix, ever.

[MontrealSergiy]

A pull request is submitted. However I suggested what I think more approriate and reliable solution, which goes beyond simply checking the syntax.

However reviewer might find this over-engineered and prefer simple solution, even if it is less reliable. If needed I can draft a 'light-weight' solution as well.