Support NOT on =~/like/ilike operators

[aej]

Is your feature request related to a problem? Please describe.
I have a use case where I would like to be able to query a string column for all rows where a pattern does not match. i.e the SQL I want to run is WHERE column NOT ILIKE '%cyth%'.

Describe the solution you'd like
A new filter which is the NOT case of the :=~ operator. Perhaps :!=~. Or :not_ variants of :like and :ilike

Describe alternatives you've considered
I've not considered any alternatives - If you have an suggested workarounds, I'd be interested.

Additional context
n/a

[woylie]

We can add :not_like and :not_ilike operators. Do you want to open a PR?

[aej]

We can add :not_like and :not_ilike operators. Do you want to open a PR?

Fantastic. Yep I'll have a go at implementing this.