make ConfigValidator source control specific

[vincent-fuchs]

Summary

we currently have a generic ConfigValidator that we apply for all source control system we manage (Github, GitLab, Azure Devops), but we see a need to sometimes have specific ConfigValidator

Type of Issue

It is a :

• [ ] bug
• [x ] request
• [ ] question regarding the documentation

Motivation

cleaner code and design

Your Environment

• Version used: 2.0.1

[vincent-fuchs]

for instance, for BitBucket config, organization is not necessary because it's not used. but because of the generic ConfigValidator inherited from the time when we supported only Github, it is mandatory to provide a value, otherwise the crawler won't start

note : it's actually used in GitHubCrawler - but not in RemoteBitBucketImpl where only projectName is used.. definnitely something to improve here