Feature request: support deleting lines that match a given pattern

[Treit]

It is sometimes useful when doing refactorings to delete a line that matches a given pattern instead of replacing it with some text.

Adding a feature to fastmod to allow deleting the matching line instead of replacing it would be a nice addition.

[SapiensAnatis]

Potential workaround: modify the regex to be e.g. .*needle.*\n and pass "" as the replacement. This doesn't work for multiline mode though, as it will propose to delete the entire file.