[KYUUBI #2277] Inline kyuubi prefix in KyuubiConf

### _Why are the changes needed?_

Inline `kyuubi.` prefix in `KyuubiConf` to keep consistently with the document and make searching friendly.

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [x] [Run test](https://kyuubi.apache.org/docs/latest/develop_tools/testing.html#running-tests) locally before make a pull request

Closes #2277 from pan3793/conf.

Closes #2277

cca77cc [Cheng Pan] fixup
9c38925 [Cheng Pan] Inline kyuubi prefix in KyuubiConf

Authored-by: Cheng Pan <chengpan@apache.org>
Signed-off-by: Kent Yao <yao@apache.org>

externals/kyuubi-trino-engine/src/main/scala/org/apache/kyuubi/engine/trino/TrinoConf.scala

@@ -27,14 +27,14 @@ object TrinoConf {
   private def buildConf(key: String): ConfigBuilder = KyuubiConf.buildConf(key)
 
   val DATA_PROCESSING_POOL_SIZE: ConfigEntry[Int] =
-    buildConf("trino.client.data.processing.pool.size")
+    buildConf("kyuubi.trino.client.data.processing.pool.size")
       .doc("The size of the thread pool used by the trino client to processing data")
       .version("1.5.0")
       .intConf
       .createWithDefault(3)
 
   val CLIENT_REQUEST_TIMEOUT: ConfigEntry[Long] =
-    buildConf("trino.client.request.timeout")
+    buildConf("kyuubi.trino.client.request.timeout")
       .doc("Timeout for Trino client request to trino cluster")
       .version("1.5.0")
       .timeConf