Avatar metadata for BitBucket organization folder is reworked

[duemir]

Since code is already has conditional branches for Server vs Cloud, handling of Avatar Metadata was split from single Action into two separate one. This enabled:

• Deprecating the copypaste of Avatar caching logic.
• Simplifying the BitBucket Cloud avatar metadata action
• Re-working the BitBucket Server avatar metadata action to avoid capturing the copy of a credential.

Related to:

• https://issues.jenkins.io/browse/JENKINS-61200
• Bitbucket users being blocked on "Scan Organization Folder" and pipelines #331
• Authentication failure when downloading avatar.png #321
• follows-up [JENKINS-61200] in case of authentication issue downloading avatar, refresh credentials and make cache time configurable #637

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[duemir]

@olamy @Dohbedoh can you check this out? It is not done but shows an alternative approach to Avatar loading that should work for all credential stores, not just system.
FYI @lifeofguenter

[duemir]

I checked all the OSS plugins that depend on bitbucket-branch-source, none of which use src/main/java/com/cloudbees/jenkins/plugins/bitbucket/avatars/UrlAvatarCacheSource.java, which is why I just deleted it.

[lifeofguenter]

Thanks for your contribution <3 - would it be possible to fix the spotbugs issues?

[donkee]

@duemir Any chance you could finish this PR?

[duemir]

@donkee I'd love to. I'm just finding it hard to get some focus time for the work.

[pniederlag]

Can we somehow help? It's a constant source of pain for anyone with expiring tokens/passwords.