Drop the provider discovery feature from the UI

[skateman]

As discussed in #6851 I'm removing this from the UI.

Resolves #6851

[h-kataria]

@skateman test failure looks related.

[miq-bot]

Checked commit skateman@fbf14d5 with ruby 2.6.3, rubocop 0.82.0, haml-lint 0.35.0, and yamllint
16 files checked, 1 offense detected

**

• 💣 💥 🔥 🚒 - Linter/Haml - Linter::Haml STDERR:

warning: parser/current is loading parser/ruby26, which recognizes
warning: 2.6.6-compliant syntax, but you are running 2.6.3.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.

[Fryguy]

cc @chessbyte @agrare @jrafanie ✂️

[h-kataria]

Ready to be merged, waiting for Travis to be green.