Update registered content templates - institution_id and source_id focused

[durack1]

Create templates to register institution_id and source_id with DRCDP-project relevant content for use in data creation

Some relevant templates
WCRP-CMIP/WCRP-universe/.github/ISSUE_TEMPLATE/add_institution.yml
WCRP-CMIP/CMIP7_CVs/.github/ISSUE_TEMPLATE/cmipld_experiment.yml (map to source_id content)

As part of issue templates, generate code to interrogate API, extract form-generated information and submit a PR. For e.g., see https://api.github.com/repos/PCMDI/DRCDP/issues/30