Move miq_tempfile here

[djberg96]

Let's move miq_tempfile.rb here, since smartstate is the only repo that uses it.

Part of the checklist for ManageIQ/manageiq-gems-pending#231

I put it under lib since the gem configuration should make it available, but I can put it directly in the OpenStackExtract/MiqOpenStackVmdirectory if you prefer.

[Fryguy]

@agrare Please review.

[miq-bot]

Checked commit https://github.com/djberg96/manageiq-smartstate/commit/f593a0e3239895ec2b775bba7ed0c7d1bc9b4290 with ruby 2.5.7, rubocop 0.69.0, haml-lint 0.28.0, and yamllint
2 files checked, 1 offense detected

lib/OpenStackExtract/MiqOpenStackVm/MiqOpenStackInstance.rb

• ❗ - Line 1, Col 1 - Naming/FileName - The name of this source file (MiqOpenStackInstance.rb) should use snake_case.

[agrare]

I'm good with this to get it extracted from gems-pending, but it looks like we could probably just stick with standard Tempfile here so maybe some follow-up refactoring