Provide a Maven pom cache for local Maven repository

[fabapp2]

What needs to be done

A new MavenPomCache implementation should be provided that uses the local Maven repository to cache downloaded pom files.

Why it needs to be done

Currently, only RocksDBMavenPomCache and InMemoryPomCache exist.
With RocksDBMavenPomCache we faced problems with locked dirs every now and then.
With the ´InMemoryMvenPomCache` poms are not persisted and bandwidth is wasted and Internet connection required when running a build.

Acceptance Criteria

Additional Information

The MavenPomCache API expects a Pom which is the model representation of a pom file but can't be serialized to a text file.

[fabapp2]

• The MavenPomDownloader uses a MavenPomCache to store and retrieve pom files. Two implementations currently exist: InMemoryMavenPomCache and RocksDbMavenPomCache.
• Providing a custom implementation to serialize Pom objects provided to the cache to the local Maven repository requires full de-/serialiation of Pom to pom file and vice versa
• The pom files written to the local Maven repository must be readable by Maven

Because Poms can contain more information (e.g. repository.username and repository.password) than a pom file can hold (xsd) it is not possible to implement this issue at the moment.