When editing a constraint that uses a context field with legal values:
if the contraint has a value that has been deleted from the legal values
of the context field:
- Show the value and mark it as disabled
- On any change -> 'cleans'/removed the deleted legal values from the
constraint values
Closes:
[1-1209](https://linear.app/unleash/issue/1-1209/if-i-modified-the-legal-values-of-a-used-context-field)
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Signed-off-by: andreas-unleash <andreas@getunleash.ai>
