[kueuectl] Add create resourceflavor command.

[mbobrovskyi]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Add kueuectl create resourceflavor command.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

CLI: Added create resourceflavor command.