Backport of Ignore existing package hashes for providers lock command into v1.2

[teamterraform]

Backport

This PR is auto-generated from #31389 to be assessed for backporting due to the inclusion of the label 1.2-backport.

The below text is copied from the body of the original PR.

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This PR addresses part of the concerns raised in #29958

First, the terraform providers lock command will now ignore any existing hashes in the .terraform.lock.hcl file. It will retrieve new hashes as if there were none already logged and then merge any new hashes into the existing list. There is now no validation of any existing hashes. It does this with the introduction of the InstallNewProvidersForce InstallMode, which is set within providers_lock.go.

Second, the output of the terraform providers lock has been made more verbose. There are three cases tracked for each (provider,platform) pair requested:

1. There were existing checksums, and nothing new was found or recorded.
2. There were existing checksums, and new checksums were found and recorded.
3. There were no existing checksums, and new checksums have been found and recorded.

Full example output:

- Fetching hashicorp/google 4.27.0 for darwin_arm64...
- Retrieved hashicorp/google 4.27.0 for darwin_arm64 (signed by HashiCorp)
- Fetching hashicorp/null 3.1.0 for darwin_arm64...
- Retrieved hashicorp/null 3.1.0 for darwin_arm64 (signed by HashiCorp)
- Fetching hashicorp/aws 4.21.0 for darwin_arm64...
- Retrieved hashicorp/aws 4.21.0 for darwin_arm64 (signed by HashiCorp)
- Obtained hashicorp/null checksums for darwin_arm64; All checksums for this platform were already tracked in the lock file
- Obtained hashicorp/aws checksums for darwin_arm64; Additional checksums for this platform are now tracked in the lock file
- Obtained hashicorp/google checksums for darwin_arm64; This was a new provider and the checksums for this platform are now tracked in the lock file

Success! Terraform has updated the lock file.

Review the changes in .terraform.lock.hcl and then commit to your
version control system to retain the new checksums.

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