Adding ability to utilize different git compatible/local folder as unique namespace for sdrf yaml template

[noatgnu]

Adding ability to utilize specific "namespace" as source of the yaml. This would be specifically powerful for organization and development of yaml onward. Example use case can be

name: human
namespace: github.com/bigbio/phosphoproteomics-sdrf-template
extends: minimum

If the resource is a git compatible resource, it will first look into github.com/bigbio/phosphoproteomics-sdrf-template, load all yaml at root and identify the minimum template to extend. We can also have it automatically detect namespace to extend.

name: human
extends: github.com/bigbio/phosphoproteomics-sdrf-template/minimum

The above would perform the same but we do not have to specify a separate namespace. This feature would make independent yaml development a lot easier as well as keeping template name simple.