Release v1.14.5, v1.15.2 & v2.1.0

[hylkevds]

Versions v1.14.5 and v1.15.2 are maintenance releases with only updated dependencies.

FROST-Server version 2.1.0 and higher requires Java 17. This is because some libraries that are used do now require Java 17.

The most important new features in Version 2.1.0:

• The new setting plugins.coreModel.editableDsProperties to control if generated (Multi)Datastream properties can be directly edited.
• Allow BasicAuthProvider to use hashed passwords. (Thanks pbaumard)
• Added option to set PostgreSQL role to enable Row-Level Security for HTTP. (Thanks pbaumard)
• Implemented unlinking many-to-many relations. This makes it possible to remove references from many-to-many relations, like Thing <-> Location and MultiDatastream <-> ObservedProperty.