Refactor detail map view, update OpenLayers and remember image zoom

[thomaslow]

This pull request refactors the ol_custom.js Javascript code, updates its OpenLayers dependency from v5.2.0 to v6.14.1 and fixes #5796. New features include:

• position, zoom and rotation of images are remembered when selecting new images
• a new control button allows to scale the image to best fit the current available space
• the OpenLayer constraints feature is enabled, such that the image can never be moved outside of the viewport
• Integration tests of zoom in, zoom out, set north, rotate left, rotate right and zoom reset buttons

Tested with Firefox, Chrome and Android Tablet (touch gestures).

Demo:

2024-09-27.13-45-26.mp4

[solth]

@thomaslow Please rebase against current master to avoid failing builds caused by broken Selenium tests!