Call ListRepoNames from search code

Created by: asdine

This PR is the same as https://github.com/sourcegraph/sourcegraph/pull/16590 which was reverted because the externalRepository.ServiceType GraphQL API was empty. This is fixed by https://github.com/sourcegraph/sourcegraph/pull/16713 which ensures we always access repository information through a hydrated repository.

This PR changes the search code to use the new dedicated ListRepoNames method that only lists repository ids and names. Fixes #16219 (closed)

Created by: sourcegraph-bot

Notifying subscribers in CODENOTIFY files for diff 7599d85c8a39a40636ae0ec2fe76bd2ea77bd66a...d93c3388702ae93ce31ab80396926e09c980debe.

Notify	File(s)
@LawnGnome	internal/db/repos.go internal/db/repos_mock.go
@beyang	internal/search/repo_revs.go
@eseliger	internal/db/repos.go internal/db/repos_mock.go
@keegancsmith	cmd/frontend/graphqlbackend/search.go cmd/frontend/graphqlbackend/search_alert_test.go cmd/frontend/graphqlbackend/search_commits.go cmd/frontend/graphqlbackend/search_commits_test.go cmd/frontend/graphqlbackend/search_pagination.go cmd/frontend/graphqlbackend/search_pagination_test.go cmd/frontend/graphqlbackend/search_progress_test.go cmd/frontend/graphqlbackend/search_repositories.go cmd/frontend/graphqlbackend/search_repositories_test.go cmd/frontend/graphqlbackend/search_results.go cmd/frontend/graphqlbackend/search_results_test.go cmd/frontend/graphqlbackend/search_structural.go cmd/frontend/graphqlbackend/search_structural_test.go cmd/frontend/graphqlbackend/search_suggestions.go cmd/frontend/graphqlbackend/search_suggestions_test.go cmd/frontend/graphqlbackend/search_symbols.go cmd/frontend/graphqlbackend/search_test.go cmd/frontend/graphqlbackend/textsearch.go cmd/frontend/graphqlbackend/textsearch_test.go cmd/frontend/graphqlbackend/zoekt.go cmd/frontend/graphqlbackend/zoekt_test.go internal/search/repo_revs.go

Created by: asdine

@keegancsmith I'm adding you as reviewer because the changes you are currently working on affect this PR as well

Created by: keegancsmith

@keegancsmith I'm adding you as reviewer because the changes you are currently working on affect this PR as well

Ok will take a look this morning.