Convert unique keys in 3 tables to primary keys (#115421)

* Added method for adding migrations for convering unique to primary key.

Based on existing migration for `file` table (in `db_file_storage.go`) migrations.

* Added better default migration names. Added ability to override migration name.

* Use ConvertUniqueKeyToPrimaryKey for cloud_migration_snapshot_partition table.

* Convert resource_version UQE to PK.

* Convert secret_encrypted_value UQE to PK.

* Removed extra test.

* Removed testdata.

* Remove support for renaming migrations for now. We can bring it in later, when we want to convert existing migrations for file, file_meta and setting tables.

* Revert removal of ColumnName to ease backporting, since this field is referenced from enterprise code.

* Use quoted identifiers in Postgres statement.

pkg/services/sqlstore/migrator/testing.go

@@ -0,0 +1,51 @@
+package migrator
+
+import (
+	"fmt"
+	"strings"
+)
+
+type ExpectedMigration struct {
+	Id  string
+	SQL string
+}
+
+// CheckExpectedMigrations verifies that given migrations exist in migrator after running addMigrations function,
+// that they are in the same order and have expected SQL.
+func CheckExpectedMigrations(dialectName string, expected []ExpectedMigration, addMigrations func(migrator *Migrator)) error {
+	d := NewDialect(dialectName)
+	mg := newMigrator(nil, nil, "", d)
+	addMigrations(mg)
+
+	migrations := mg.migrations
+	migrationNames := make([]string, 0, len(migrations))
+	for _, m := range expected {
+		for ; len(migrations) > 0 && migrations[0].Id() != m.Id; migrations = migrations[1:] {
+			migrationNames = append(migrationNames, migrations[0].Id())
+		}
+
+		if len(migrations) == 0 {
+			return fmt.Errorf("migration `%s` not found, existing migrations:\n%s", m.Id, strings.Join(migrationNames, "\n"))
+		}
+
+		sql := migrations[0].SQL(d)
+		if normalizeLines(m.SQL) != normalizeLines(sql) {
+			return fmt.Errorf("migration `%s` has wrong SQL:\nexpected:\n%s\nactual:\n%s", m.Id, m.SQL, sql)
+		}
+	}
+	return nil
+}
+
+func normalizeLines(sql string) string {
+	lines := strings.Split(sql, "\n")
+	result := strings.Builder{}
+	for _, l := range lines {
+		l := strings.TrimSpace(l)
+		if l == "" {
+			continue
+		}
+		result.WriteString(l)
+		result.WriteString("\n")
+	}
+	return result.String()
+}