Allow a new option in the BB Server configuration to use global workspace webhooks, this will only manage a single webhook per BB Workspace, instead of individual webhooks per repository

https://support.atlassian.com/bitbucket-cloud/kb/how-to-create-workspace-level-webhooks/

https://developer.atlassian.com/cloud/bitbucket/rest/api-group-workspaces/#api-workspaces-workspace-hooks-get

Why? 

When creating a new Org Folder for BitBucket, it will try to create webhooks for all the repositories linked to the workspace (based on the current filter).

In case we are doing it for a workspace with a large number of repositories,  the plugin can reach the WebHook rate limit.

 
As explained in https://support.atlassian.com/bitbucket-cloud/docs/api-request-limits/
the quota for webhooks is 1000 calls / hour

Access to webhook data
Limited to the following actions across a workspace or repositories:
List all webhooks 
Add webhooks
Remove webhooks
-----------------------
1,000 per hour

So when creating a new Org Folder (or scanning the organization), for each repository we are:

• Checking if the webhook is aready created
• If not, create the webhook in the repo

So it is easy we reach the limit and there will be some repos where the webhook is never created if the repo number is big (more than 1000).

With the new approach, we just need to check it once, and create once for the full workspace.