Various fixes

[NicoPennec]

Problem

• Mark As Read button & individual notification status is broken #1629
• Asset Path UI Path Overlap #1643
• Start and Due Date calendars should stick out, instead of being wrapped in a task column #1626

Solution

• Fix a wrong state on the "read" notification button (issue due to vue3 migration).
• Improve the display of metadata in read-only mode, in order to avoid UX overflow.
• Fix the visibility of the date picker if hidden overflow. Thanks to the "teleport" option from the date picker lib.

[frankrousseau]

Thx!