Only search for relationships if there are accounts (#1187)

Otherwise this would lead to a `badRequest`

Mastodon/Scene/Search/SearchDetail/SearchResult/SearchResultViewModel+State.swift

@@ -125,10 +125,15 @@ extension SearchResultViewModel.State {
 
                     let accounts = searchResults.accounts
 
-                    let relationships = try await viewModel.context.apiService.relationship(
+                    let relationships: [Mastodon.Entity.Relationship]
+                    if accounts.isNotEmpty {
+                        relationships = try await viewModel.context.apiService.relationship(
                             forAccounts: accounts,
                             authenticationBox: viewModel.authContext.mastodonAuthenticationBox
                         ).value
+                    } else {
+                        relationships = []
+                    }
 
                     let statusIDs = searchResults.statuses.map { $0.id }