Make repo compliant

[RaphaelVogel]

What this PR does / why we need it:

• Updated CONTRIBUTING.md file
• Created/Updated LICENSE file
• Created/Updated .reuse/dep5 file
• Created/Updated LICENSES folder
• Added badge for reuse compliance in README.md file and registered repo with REUSE API
• License/Copyright header replacement for 'non-go' files
  • .ci/test
  • .ci/build
  • .ci/check
• License/Copyright header replacement for 'go' files
  • cluster-autoscaler/cloudprovider/mcm/machine_client_builder.go
  • cluster-autoscaler/cloudprovider/mcm/test_utils.go
  • cluster-autoscaler/cloudprovider/mcm/mcm_cloud_provider_test.go
  • cluster-autoscaler/cloudprovider/mcm/fakeclient/client.go

[RaphaelVogel]

@rishabh-11 some additional info. To keep this repository compliant, CODEOWNERS must maintain their third party dependencies in the vendor folder using .reuse/dep5 file. To prevent constant maintenance effort, it is highly recommended to remove the vendor folder. In this case no third party dependencies of the vendor folder must be maintained anymore!

[rishabh-11]

@RaphaelVogel the upstream has not removed the vendor directory yet. It will cause problems for us while syncing the fork if we remove the vendor in our fork