[PECOBLR-1338] fix isNullOrEmpty check for schemaNamePattern in SEA (databricks#1119)

## Description
<!-- Provide a brief summary of the changes made and the issue they aim
to address.-->
Fix incorrect schemaPattern check in SEA metadata commands

Repro:
```
    ResultSet rs = con.getMetaData().getTables("main", "", "%", null);
```
Above code snippet should return empty result. Same as thrift

## Testing
<!-- Describe how the changes have been tested-->
- Unit test
- Verified that repro snippet behaves accordingly

## Additional Notes to the Reviewer
<!-- Share any additional context or insights that may help the reviewer
understand the changes better. This could include challenges faced,
limitations, or compromises made during the development process.
Also, mention any areas of the code that you would like the reviewer to
focus on specifically. -->

NO_CHANGELOG=true

Author: shivam2680

src/main/java/com/databricks/jdbc/dbclient/impl/sqlexec/CommandBuilder.java

@@ -87,7 +87,7 @@ private String fetchSchemaSQL() {
     } else {
       showSchemasSQL = String.format(SHOW_SCHEMAS_IN_CATALOG_SQL, catalogName);
     }
-    if (!WildcardUtil.isNullOrEmpty(schemaPattern)) {
+    if (schemaPattern != null) {
       showSchemasSQL += String.format(LIKE_SQL, schemaPattern);
     }
     return showSchemasSQL;
@@ -107,10 +107,10 @@ private String fetchTablesSQL() {
     } else {
       showTablesSQL = String.format(SHOW_TABLES_SQL, catalogName);
     }
-    if (!WildcardUtil.isNullOrEmpty(schemaPattern)) {
+    if (schemaPattern != null) {
       showTablesSQL += String.format(SCHEMA_LIKE_SQL, schemaPattern);
     }
-    if (!WildcardUtil.isNullOrEmpty(tablePattern)) {
+    if (tablePattern != null) {
       showTablesSQL += String.format(LIKE_SQL, tablePattern);
     }
     return showTablesSQL;
@@ -125,15 +125,15 @@ private String fetchColumnsSQL() throws DatabricksSQLException {
     throwErrorIfNull(Collections.singletonMap(CATALOG, catalogName), contextString);
     String showColumnsSQL = String.format(SHOW_COLUMNS_SQL, catalogName);
 
-    if (!WildcardUtil.isNullOrEmpty(schemaPattern)) {
+    if (schemaPattern != null) {
       showColumnsSQL += String.format(SCHEMA_LIKE_SQL, schemaPattern);
     }
 
-    if (!WildcardUtil.isNullOrEmpty(tablePattern)) {
+    if (tablePattern != null) {
       showColumnsSQL += String.format(TABLE_LIKE_SQL, tablePattern);
     }
 
-    if (!WildcardUtil.isNullOrEmpty(columnPattern)) {
+    if (columnPattern != null) {
       showColumnsSQL += String.format(LIKE_SQL, columnPattern);
     }
     return showColumnsSQL;
@@ -148,10 +148,10 @@ private String fetchFunctionsSQL() throws DatabricksSQLException {
     LOGGER.debug(contextString);
     throwErrorIfNull(Collections.singletonMap(CATALOG, catalogName), contextString);
     String showFunctionsSQL = String.format(SHOW_FUNCTIONS_SQL, catalogName);
-    if (!WildcardUtil.isNullOrEmpty(schemaPattern)) {
+    if (schemaPattern != null) {
       showFunctionsSQL += String.format(SCHEMA_LIKE_SQL, schemaPattern);
     }
-    if (!WildcardUtil.isNullOrEmpty(functionPattern)) {
+    if (functionPattern != null) {
       showFunctionsSQL += String.format(LIKE_SQL, functionPattern);
     }
     return showFunctionsSQL;

src/test/java/com/databricks/jdbc/dbclient/impl/sqlexec/CommandBuilderTest.java

@@ -148,6 +148,39 @@ void shouldGenerateCorrectSqlForTablesWithWildcardCatalog() throws SQLException
       String sql1 = builder1.getSQLString(CommandName.LIST_TABLES);
       assertEquals(SHOW_TABLES_IN_ALL_CATALOGS_SQL, sql1);
     }
+
+    @Test
+    @DisplayName("Should generate SCHEMA LIKE clause for empty string schema pattern")
+    void shouldGenerateSchemaLikeClauseForEmptyStringSchemaPattern() throws SQLException {
+      CommandBuilder builder = new CommandBuilder(TEST_CATALOG, mockSession).setSchemaPattern("");
+
+      String sql = builder.getSQLString(CommandName.LIST_TABLES);
+
+      String expectedSql = String.format(SHOW_TABLES_SQL.concat(SCHEMA_LIKE_SQL), TEST_CATALOG, "");
+      assertEquals(expectedSql, sql);
+    }
+
+    @Test
+    @DisplayName("Should NOT generate SCHEMA LIKE clause for null schema pattern")
+    void shouldNotGenerateSchemaLikeClauseForNullSchemaPattern() throws SQLException {
+      CommandBuilder builder = new CommandBuilder(TEST_CATALOG, mockSession).setSchemaPattern(null);
+
+      String sql = builder.getSQLString(CommandName.LIST_TABLES);
+
+      String expectedSql = String.format(SHOW_TABLES_SQL, TEST_CATALOG);
+      assertEquals(expectedSql, sql);
+    }
+
+    @Test
+    @DisplayName("Should generate LIKE clause for empty string table pattern")
+    void shouldGenerateLikeClauseForEmptyStringTablePattern() throws SQLException {
+      CommandBuilder builder = new CommandBuilder(TEST_CATALOG, mockSession).setTablePattern("");
+
+      String sql = builder.getSQLString(CommandName.LIST_TABLES);
+
+      String expectedSql = String.format(SHOW_TABLES_SQL.concat(LIKE_SQL), TEST_CATALOG, "");
+      assertEquals(expectedSql, sql);
+    }
   }
 
   @Nested