Split `integrations.bitbucket` into `integrations.bitbucketCloud`
and `integrations.bitbucketServer`
while staying backwards compatible for now
(== `BitbucketIntegration` loads from the new configs, too, if the old is not used).
Relates-to: #9923
Signed-off-by: Patrick Jungermann <Patrick.Jungermann@gmail.com>