Support migration from AWS CodeCommit (#31981)

This PR adds support for migrating repos from [AWS
CodeCommit](https://docs.aws.amazon.com/codecommit/latest/userguide/welcome.html).

The access key ID and secret access key are required to get repository
information and pull requests. And [HTTPS Git
credentials](https://docs.aws.amazon.com/codecommit/latest/userguide/setting-up-gc.html)
are required to clone the repository.

<img
src="https://github.com/user-attachments/assets/82ecb2d0-8d43-42b0-b5af-f5347a13b9d0"
width="680" />

The AWS CodeCommit icon is from [AWS Architecture
Icons](https://aws.amazon.com/architecture/icons/).

<img
src="https://github.com/user-attachments/assets/3c44d21f-d753-40f5-9eae-5d3589e0d50d"
width="320" />

routers/api/v1/repo/migrate.go

@@ -169,6 +169,10 @@ func Migrate(ctx *context.APIContext) {
 		opts.PullRequests = false
 		opts.Releases = false
 	}
+	if gitServiceType == api.CodeCommitService {
+		opts.AWSAccessKeyID = form.AWSAccessKeyID
+		opts.AWSSecretAccessKey = form.AWSSecretAccessKey
+	}
 
 	repo, err := repo_service.CreateRepositoryDirectly(ctx, ctx.Doer, repoOwner, repo_service.CreateRepoOptions{
 		Name:           opts.RepoName,