Suggestion: modify tinyint to string conversion (#1053)

## Description
Currently the conversion from tinyint to string is done using
`String(byte[])` which depends on the platform's default charset and
also is
[unspecified](https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#String-byte:A-)
when the bytes are not valid in the default charset (e.g. may produce
"?" instead of a sensible value).

## Testing
Tested with the existing unit tests.

## Additional Notes to the Reviewer
-

---------

Signed-off-by: Ivan Vankov <ivan.vankov@workato.com>
Co-authored-by: Samikshya Chand <148681192+samikshya-db@users.noreply.github.com>

Author: vankovivan

NEXT_CHANGELOG.md

@@ -11,5 +11,6 @@
 ### Fixed
 - Fixed: Errors in table creation when using BIGINT, SMALLINT, TINYINT, or VOID types.
 - Fixed: PreparedStatement.getMetaData() now correctly reports TINYINT columns as Types.TINYINT (java.lang.Byte) instead of Types.SMALLINT (java.lang.Integer).
+- Fixed: TINYINT to String conversion to return numeric representation (e.g., "65") instead of character representation (e.g., "A").
 ---
 *Note: When making changes, please add your change under the appropriate section with a brief description.* 

src/main/java/com/databricks/jdbc/api/impl/converters/ByteConverter.java

@@ -66,6 +66,6 @@ public byte[] toByteArray(Object object) throws DatabricksSQLException {
 
   @Override
   public String toString(Object object) throws DatabricksSQLException {
-    return new String(new byte[] {toByte(object)});
+    return String.valueOf(toByte(object));
   }
 }

src/test/java/com/databricks/jdbc/api/impl/converters/ByteConverterTest.java

@@ -7,6 +7,8 @@
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
 
 public class ByteConverterTest {
   private final byte NON_ZERO_OBJECT = 65;
@@ -74,9 +76,10 @@ public void testConvertToChar() {
     assertTrue(exception.getMessage().contains("Unsupported char conversion operation"));
   }
 
-  @Test
-  public void testConvertToString() throws DatabricksSQLException {
-    assertEquals(new ByteConverter().toString(NON_ZERO_OBJECT), "A");
+  @ParameterizedTest
+  @CsvSource({"-128, -128", "-1, -1", "0, 0", "1, 1", "10, 10", "65, 65", "127, 127"})
+  public void testConvertToString(byte input, String expected) throws DatabricksSQLException {
+    assertEquals(new ByteConverter().toString(input), expected);
   }
 
   @Test