Add cloud creds support for terraform runner

[putmanoj]

• Add cloud credentials classes for embedded-terraform with DDF configuration
• Add cloud credentails classes with authentication connection parameters for terraform-runner

[jrafanie]

With https://github.com/ManageIQ/manageiq-providers-embedded_terraform/pull/3 and https://github.com/ManageIQ/manageiq-ui-classic/pull/9117 (rebased) locally and this PR... here are some screenshots of the credentials we're defining here:

amazon:

azure:

google:

ibm cloud (quite wordy)

openstack 1:

openstack 2:

scm:

vsphere:

[miq-bot]

Checked commits https://github.com/putmanoj/manageiq-providers-embedded_terraform/compare/816f9c8859fd95703d2b34ca531b5c8bfe2a0eee~...101cd1724ce1d33921ca9bd364d29dd13691d672 with ruby 2.7.8, rubocop 1.56.3, haml-lint 0.51.0, and yamllint 32 files checked, 0 offenses detected Everything looks fine. :+1: