fix: recognize ABORT statements for PostgreSQL (#2479)

PostgreSQL supports the `ABORT [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ]`
statement in addition to the more common ROLLBACK.

See https://www.postgresql.org/docs/current/sql-abort.html

Author: olavloite

google-cloud-spanner/src/main/resources/com/google/cloud/spanner/connection/PG_ClientSideStatements.json

@@ -224,13 +224,16 @@
       "examplePrerequisiteStatements": ["begin transaction"]
     },
     {
-      "name": "ROLLBACK [TRANSACTION | WORK] [AND NO CHAIN]",
+      "name": "{ROLLBACK | ABORT} [TRANSACTION | WORK] [AND NO CHAIN]",
       "executorName": "ClientSideStatementNoParamExecutor",
       "resultType": "NO_RESULT",
       "statementType": "ROLLBACK",
-      "regex": "(?is)\\A\\s*(?:rollback)(?:\\s+transaction|\\s+work)?(?:\\s+and\\s+no\\s+chain)?\\s*\\z",
+      "regex": "(?is)\\A\\s*(?:rollback|abort)(?:\\s+transaction|\\s+work)?(?:\\s+and\\s+no\\s+chain)?\\s*\\z",
       "method": "statementRollback",
-      "exampleStatements": ["rollback", "rollback transaction", "rollback work", "rollback and no chain", "rollback transaction and no chain", "rollback work and no chain"],
+      "exampleStatements": [
+        "rollback", "rollback transaction", "rollback work", "rollback and no chain", "rollback transaction and no chain", "rollback work and no chain",
+        "abort", "abort transaction", "abort work", "abort and no chain", "abort transaction and no chain", "abort work and no chain"
+      ],
       "examplePrerequisiteStatements": ["begin transaction"]
     },
     {

google-cloud-spanner/src/test/java/com/google/cloud/spanner/connection/ClientSideStatementsTest.java

@@ -78,6 +78,22 @@ public void testClientSideStatementType() {
     assertEquals(
         ClientSideStatementType.ROLLBACK,
         parser.parse(Statement.of("ROLLBACK TRANSACTION")).getClientSideStatementType());
+    if (dialect == Dialect.POSTGRESQL) {
+      assertEquals(
+          ClientSideStatementType.ROLLBACK,
+          parser.parse(Statement.of("ABORT")).getClientSideStatementType());
+      assertEquals(
+          ClientSideStatementType.ROLLBACK,
+          parser.parse(Statement.of("ABORT TRANSACTION")).getClientSideStatementType());
+      assertEquals(
+          ClientSideStatementType.ROLLBACK,
+          parser.parse(Statement.of("ABORT WORK")).getClientSideStatementType());
+      assertEquals(
+          ClientSideStatementType.ROLLBACK,
+          parser
+              .parse(Statement.of("ABORT TRANSACTION and no chain"))
+              .getClientSideStatementType());
+    }
 
     for (ClientSideStatementImpl statement : parser.getClientSideStatements()) {
       assertNotNull(