Provide DELETE support for Bitbucket Build API

Bitbucket is receiving the build results from connected CI systems via Bitbucket Build REST API using the commit hash and the build key combination to identify the builds.

In case of failed build it's possible to send the update via REST API to identify it as successful.

However it's impossible to remove the existing build result, which has business impact in case of build configuration mistakes:

1. It ran on the wrong agent.
2. There was a configuration issue with the agent that needed to be resolved.
3. They were actually going for re-run rather than a new build but mistakenly chose the wrong option.
4. The incorrect build configuration was in use.
5. The build was stopped rather than failed, which results in a failure result appearing in Bitbucket.

It would be good to have the possibility to DELETE the build results via REST API in order to provide the possibility to keep the builds in CI and in Bitbucket in sync.