Show which watched words entries caused a word to be matched

Currently, the watched words test feature shows what words caused an action, but not what watched words entries matched the input. This can make it harder for moderators to find and remove problematic watched words, especially when wildcards are involved.
For example, with only *f*t*p* added to the Require Approval Watched Words list, it may be hard to know which entries matched this input:
If the UI showed which entries matched the input, it’d make debugging watched words entries easier (for example, certain watched words configurations can block seemingly random links for no apparent reason, and it’s currently difficult to find the culprit).