[feature] {tokens} in notification URLs

[1-Samuel]

Version and OS
0.39.15 on linux/docker

Describe the solution you'd like
I would like the notification tokens ({base_url}, {watch_url}, ...) to be usable not only in the notification title and body, but also in the notification URLs.

Describe the use-case and give concrete real-world examples
With tokens in the URLs it would be possible to add dynamic parameters for the notification services.

An example would be the click parameter for ntfy which enables the notification to open a link on click. Possible useful values would be {watch_url}, {preview_url}, {diff_url}.

This notification would directly open the URL of the watched item on click:
ntfy://ntfy.sh/example?click={watch_url}

[dgtlmoon]

#289 already exists, but was blocked because we didnt have an update mechanism, but we have it now

[dgtlmoon]

Just fixed a huge bunch of problems in the extract text filter (#773) so this would be a nice one to solve next

[dgtlmoon]

related to #1063 & #289

[dgtlmoon]

solved in latest dev!