feat(release): support bitbucket cloud releases

[viqueen]

Fixes #12

Context

• supports releasing to bitbucket cloud repository
• it does not include resolving an issue tracker (yet) , to be continued
  • we can support default issue tracker first with bitbucket cloud group issue tracker api
  • and explore integration with jira for [version/release management}(https://support.atlassian.com/jira-software-cloud/docs/enable-releases-and-versions/)
• it includes artifact upload to bitbucket cloud
• note:
  • I ran into some issues with git push using ssh locally, other than that everything works fine with repo access tokens and https remotes

Checklist

• Review Contribution Guidelines.

• Make sure all contributed code can be distributed under the terms of the
  Apache License 2.0, e.g. the code was written by
  you or the original code is licensed under a license compatible to Apache License 2.0.

• Update documentation when applicable.

• register BitbucketcloudUploader with JsonSchemaGenerator

• use Templates.resolveTemplate() where applicable

• use bitbucket dsl with mode set to CLOUD vs DC/SERVER

[CLAassistant]

All committers have signed the CLA.

[aalmiray]

Is there a significant API difference between BBC and BBS? I'd suppose some would like to use their own BBS instance when running on premise.

[viqueen]

Is there a significant API difference between BBC and BBS? I'd suppose some would like to use their own BBS instance when running on premise.

Historically they are different products, so there's definitely a difference in the API endpoints, but also in access token management.

[aalmiray]

Would it make sense to support both with a single DSL element named bitbucket and additional enum property mode with CLOUD and SERVER as value?

The reason I ask is that both GitHub and Gitlab support managed and self hosted services with a single DSL element because the only difference at the moment is the host's value, given that the API is the same for both scenarios.

[aalmiray]

I'm thinking that support for BBS may be added later based on user request. Both BBC & BBS could be supported by a single DSL element as previously suggested, in which case bitbucketcloud would be deprecated in favor of bitbucket.

[aalmiray]

project identifier might contain name templates which should be resolved before calling the api. Use Templates.resolveTemplate() to get the resolved value.

[aalmiray]

This uploader should be registered with JsonSchemaGenerator in the same way as others uploaders have been registered.