RemoveResource for not existed resources

[sealbro]

Hi, @gmichels ! Thank you for the helpful provider

I had a problem when somebody removed resources from UI or used API. When it happens, you can't apply your changes and should add them, or nothing will apply.

What changed:

• Changes a few Error diagnostic messages to Warning and call RemoveResource like hashicorp recommended. After that, it applies like a new one.
• Little changed blacklist test because Adguard timeouts (set_url) applies filter_5.txt(I don't want to extend provider timeout)
• Makefile
  • Improved cleanup after failed tests for testacc
  • Explicitly added GOOS and GOARCH because they help build for different platforms.
  • Created TERRAFORM_PLUGINS environment for plugin path for flexibility with multiple terraform
  • Added help command
• Other changes
  • Changed adguard version to the latest for now
  • Removed deprecated docker-compose version
  • Added .idea into .gitingnore

[sealbro]

Few screenshots

Delete not existing in adguard resources (terraform output)

make help command

[gmichels]

Hey @sealbro, thanks for the PR. Tests are failing on the cleanup you added, so they need reverted. I will also make some minor verbiage/cosmetic suggestions on the code.

[gmichels]

The tests have passed just fine. I will try to look further into why the timeout is happening, but for this PR, I believe we are looking good.

Thanks for the contribution.