MSS 6.2.0

This release includes the use of the new basemap-1.3.3 release and enables packaging for python 3.10.x.
We added the possibility of flight level as vertical coordinate.
A user can now leave on his own an operation.

All Changes:
https://github.com/Open-MSS/MSS/milestone/80

What's Changed

• Adding leave operation option in properties menu by @swsrkty in #1438
• Switch testing structure to new docker images by @joernu76 in #1436
• add flight level as vertical coordinate for files by @gisi90 in #1456
• improved mss build for python 3.10 and recent basemap by @ReimarBauer in #1459
• fix always by @joernu76 in #1465

Full Changelog: 6.1.0...6.2.0