Avoid over-extracting utilities from candidates with decimal values

[adamwathan]

Prevents candidates like px-1.5 from generating both the px-1.5 class and the px-1 class.

There's a chance that the inner matches regex we're throwing away here handles some other cases that aren't currently tested, but since they aren't tested I'm assuming it's not needed. We'll find out quickly from our users if they were and can fix it then :)

Fixes #13952 and #9354 and probably a bunch of other issues that have been opened for the same thing.

[danielehrhardt]

@adamwathan all Angular Apps are broken with this PR, would be great if this could be fixed soon.
#14011