[feature] Apply "include filters" to notification screenshots (crop screenshot to filters)

**Version and OS**
v0.49.13 on Debian 12/Docker

**Is your feature request related to a problem? Please describe.**
Screenshots are way too big, and it is hard to view the content that matters.

**Describe the solution you'd like**
Add a conditioned checkbox `Apply visual filter to screenshot` (only interactable when `Attach screenshot to notification (where possible)` is checked) on the `Notifications` tab, preferably below the `Attach screenshot to notification (where possible)` checkbox.

When checked, the visual filter will be applied to the screenshot, which will be cropped to the size of the selected element.

**Describe the use-case and give concrete real-world examples**
This is how screenshots look currently:

View Image


This is how screenshots would look if they were cropped to the visual filter, in this case, the "About us" section in the footer of the changedetection.io website was selected:


**Additional context**
Let me know if something isn't clear.

Start by locating the Notifications tab and the existing screenshot attachment path. Trace how the selected visual filter and screenshot are represented, then verify that the new option is conditional on screenshot attachment and that a checked option produces a screenshot cropped to the selected element.

Written by the indexing model from the issue text.