Enable PR pipeline execution when opened

[braisvq1996]

Is your feature request related to a problem?
When a Pull Request is opened into a repository of a project the Jenkins pipeline is not executed.
It is necesary to make an aditional commit in order to trigger the jenkins build

Describe the solution you'd like
Enable PRs to tigger jenkins pipelines by default

Describe alternatives you've considered
Document how users can enable it for their components

Additional context
It needs to update the webhook proxy accepted events and the Prov-app config map, that takes the value from ods-configuration

@metmajer this is what we talked about today

[braisvq1996]

I still need to run some tests about this but this is where I think would need to be changed to enable PR pipeline execution upon creation

[tbugfinder]

it can also be configured using env var
https://github.com/opendevstack/ods-core/blob/master/jenkins/webhook-proxy/main.go#L35

[braisvq1996]

Yeah, it can be done there but Bitbucket webhook events also needs to be configured.