Adding JGitV1 and JGitV2 Walk Encryption

Adding JGitV1 and JGitV2 Walk Encryption

Building on top of https://git.eclipse.org/r/#/c/56391/

Here we preserve compatibility with JetS3t
and add 2 new native JGit encryption implementations.

For reference, see connection configuration files:
* Version 0: jgit-s3-connection-v-0.properties
* Version 1: jgit-s3-connection-v-1.properties
* Version 2: jgit-s3-connection-v-2.properties

Change-Id: I713290bcacbe92d88e5ef28ce137de73dd1abe2f
Signed-off-by: Andrei Pozolotin <andrei.pozolotin@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>