[Feat] Add cluster settings management

[thomas-tomlinson]

Requirements:

• [ ] Enable configuration of cluster settings as documented under the prism central v3 api /clusters

Todo:

• [ ] Client SDK, get_spec()
• [ ] Ansible spec & spec validator
• [ ] Unit test, sanity test
• [ ] Integration test
• [ ] Documentation
• [ ] Examples

[thomas-tomlinson]

I do not appear to have the ability to assign this issue to my self but I do have the majority of this completed. PR is attached to this issue.

[bhati-pradeep]

As v1.7 release approaching, moving it out of it and will consider it in next release