Hard-wire external associations: 3 sections in, this one is 4/7 (#645)

* Continue rebasing.

* Wrote unit tests for external associations.

* Fix the generated SQL.

Some syntactic sugar (capitalizing the keywords), but use the 'ON' syntax on JOINs.

* whitespace fix post rebase

* We want "management.cattle.io.projects:spec.displayName" not "...spec.clusterName"

* Fix the database calls: drop the key

* Fix breakage during automatic rebase merging gone wrong.

* ws fix - NFC

* Post rebase-merge fixes

* Fix rebase-driven merge.

* Fix rebase breakage.

* go-uber v0.5.2 prefers real arg names to '<argN>'

pkg/sqlcache/store/db_mocks_test.go

@@ -235,6 +235,21 @@ func (mr *MockClientMockRecorder) ReadStrings(rows any) *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ReadStrings", reflect.TypeOf((*MockClient)(nil).ReadStrings), rows)
 }
 
+// ReadStrings2 mocks base method.
+func (m *MockClient) ReadStrings2(rows db.Rows) ([][]string, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "ReadStrings2", rows)
+	ret0, _ := ret[0].([][]string)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// ReadStrings2 indicates an expected call of ReadStrings2.
+func (mr *MockClientMockRecorder) ReadStrings2(rows any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ReadStrings2", reflect.TypeOf((*MockClient)(nil).ReadStrings2), rows)
+}
+
 // Upsert mocks base method.
 func (m *MockClient) Upsert(tx transaction.Client, stmt *sql.Stmt, key string, obj any, shouldEncrypt bool) error {
 	m.ctrl.T.Helper()