Move gfdl template json: to make it accessible from intakebuilder package

[aradhakrishnanGFDL]

Following @bcc2761's fre-cli and catalogbuilder explorations, having the gfdl_test1.json outside of intakebuilder in cats/ , makes it not easily accessible to fre-cli, and there is some redundant copying of these files that may have to be done to work around the issue.

Since we wants these templates to be version controlled, maintainable, and accessible to users..in addition to inviting users to contribute more templates for their work with varying experimental designs or projects, this issue addresses moving the json file within intakebuilder.

i) Leave the cats alone for now
ii) Move https://github.com/aradhakrishnanGFDL/CatalogBuilder/blob/main/cats/gfdl_template.json to
https://github.com/aradhakrishnanGFDL/CatalogBuilder/tree/main/intakebuilder/esm-collection-spec

iii) If esm-collection-spec is better named as "templates", that's acceptable too.
(esm-collection-spec is what the intake-esm community uses. )

Renaming esm-collection-specs to templates in the catalog builder repo might make some sense, given the future considerations to have something like a templates directory (version controlled repo) within each tool that fre-cli invokes.

iv) Run tests to make sure things don't break.
note- the template gfdl_template.json is used in pytests, gen_intake_gfdl.py,

v) Brainstorm naming conventions for these templates. E.g. there can be more than one template from GFDL in the future, depending on what the user wants. This does not have to reside in this repo, but it helps to collect them.
(open an issue ..if this can't be resolved now)

[aradhakrishnanGFDL]

leave this as-is for now