Restrict export to certain area for a transect

[mzur]

Users should be able to draw a (rectangle) area for each transect to which the export can be restricted to. All annotations outside of this area are (optionally) discarded from the reports.

Ideas:

• Use the transects.attrs attribute to store the restriction area for each transect
• Implement an extension for the annotations module to draw and display the restriction area for a transect
• Offer an option "restrict area" in the reports mixin on the projects page

[mzur]

This has to wait until laravel/framework#14499 is resolved.

[mzur]

Paulo Sumida wants an "Option to delimit a perimeter to keep analysis restricted to that area". This is probably exactly what this issue is about since the only "analysis" Dias is capable of is the export feature.

[mzur]

Second attempt for PR: laravel/framework#14711