Add possibility to disable send any build notification to bitbucket

[33man]

This PR add the feature to disable notification sending to bitbucket via BitbucketBuildStatusNotificationsTrait

We basically have our own Jenkins pipeline with custom notification steps and this plugin send duplicates notifications and sometime not accurate build status. (Maybe fixed with #472 but still will end up with multiple notifications in Bitbucket Builds)

Your checklist for this pull request

• Make sure you are requesting to pull a topic/feature/bugfix branch (right side) and not your master branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or in Jenkins JIRA
• Link to relevant pull requests, esp. upstream and downstream changes
• Did you provide a test-case? That demonstrates feature works or fixes the issue.

[KalleOlaviNiemitalo]

Isn't this already doable with Skip Notifications Trait Plugin? See JENKINS-49216 / JENKINS-49471 / JENKINS-36755.

[KalleOlaviNiemitalo]

Moreover, if this PR were merged, then it might cause Skip Notifications Trait Plugin to stop working, depending on the order in which the traits are evaluated.

[33man]

Hello @KalleOlaviNiemitalo, Thanks for your comments. Indeed i wasn't aware of such extension. Sorry, i will therefore close the PR.