RFR: 1910: Basic support for Bitbucket as a Forge [v2]

[Zhao Song]

On Fri, 12 May 2023 23:00:41 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

>> This patch adds very basic support for Bitbucket as a Forge, just enough to be able to use a Bitbucket repo as the source for mirroring.
>> 
>> In order to support ssh for bitbucket, I moved the `configureSshKey` method from `GitLabForgeFactory` to a new utility class, so that it could be shared more easily.
>
> Erik Joelsson has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Review comments

LGTM

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Marked as reviewed by zsong (Committer).

PR Review: https://git.openjdk.org/skara/pull/1521#pullrequestreview-1428854558