Updating platform jobs for pluggable scm

[dsingh07]

This pull request will update miscellaneous platform jobs to support Pluggable SCM:

• A new platform job to deploy the pluggable scm library in your Job DSL additional classpath
• Updates to Generate_Project to allow you to add a new parameter to Load_Cartridge, letting you set a custom namespace for your repos to be loaded under
• Updates to Load_Cartridge with a new parameter for SCM_PROVIDER and making it completely agnostic of your chosen SCM provider i.e. no references to Gerrit
• Supports running load cartridge and masters and unix/linux slaves.

Test Scenarios

• [x] Backwards compatibility: Load current Java Cartridge ** Expect spring petclinic repos to be created in Gerrit
• [x] Backwards compatibility: Load current DOA Cartridge Collection
• [x] Test Gerrit SCM Provider with SSH (Java Cartridge)
• [x] Test Gerrit SCM Provider with SSH and without a cartridge folder name
• [x] Test Gerrit SCM Provider with HTTPS (Java Cartridge)
• [x] Test Gerrit SCM Provider with HTTPS and without a cartridge folder name (Java Cartridge)

As the build label is also set to !master the above tests should also confirm we can run the cartridge loader from unix/linux based slaves.

For all tests it is expected the respective repositories captured in urls.txt will be created with the respective SCM provider (Gerrit, BitBucket)

This PR is dependent on: https://github.com/Accenture/adop-jenkins/pull/29 https://github.com/Accenture/adop-docker-compose/pull/187 https://github.com/Accenture/adop-pluggable-scm/pull/4

[dsingh07]

Thanks for the review @nickdgriffin

I have fixed that bug now.

Waiting for this PR to get merged in: https://github.com/dsingh07/adop-platform-management/pull/1 to my branch, and this PR should be in a reviewable state again.

[dsingh07]

There have been changes introduced by @BuleGeorge and @RobertNorthard which will be tested by me, after rebasing with all the other changes that have been introduced.

I shall update this PR with exciting developments :)

[dsingh07]

Thanks for the quick review @RobertNorthard

Have made those changes that you've requested.

[RobertNorthard]

Thanks @dsingh07.

@nickdgriffin @anton-kasperovich this requires one final look over (fresh pair of eyes) before we merge.

[dsingh07]

Commits have been squashed and is ready for a final round of testing from @nickdgriffin and @anton-kasperovich :)

[RobertNorthard]

Thanks @dsingh07 added a few comments in relation to error handling. After this PR is merged, we should also merge https://github.com/Accenture/adop-cartridge-skeleton/pull/3 to demonstrate how to use the pluggable library.

[RobertNorthard]

LGTM. Thanks everyone for the hard work.

@dsingh07 @nickdgriffin @anton-kasperovich @BuleGeorge @SachinKSingh28 @MarisBahtins @IrmantasM