[improvement](jdbc catalog) Add catalog property to enable jdbc connection pool

[zy-kkk]

We initially introduced jdbc connection pool to improve the connection performance of jdbc catalog, but we always found that connection pool would bring some unexpected errors, so we chose to add a catalog property: enable_connection_pool to choose whether to enable the jdbc connection pool of jdbc catalog, and the default is still true.

And we conducted performance tests on this, the performance loss is within the expected range.

• Enable connection pool: mysqlslap -uroot -h127.0.0.1 -P9030 --concurrency=1 --iterations=100 --query='SELECT * FROM mysql.test.test limit 1;' --create-schema=mysql --delimiter=";" --verbose Benchmark Average number of seconds to run all queries: 0.008 seconds Minimum number of seconds to run all queries: 0.004 seconds Maximum number of seconds to run all queries: 0.133 seconds Number of clients running queries: 1 Average number of queries per client: 1

• Disable connection pool: mysqlslap -uroot -h127.0.0.1 -P9030 --concurrency=1 --iterations=100 --query='SELECT * FROM mysql_no_pool.test.test limit 1;' --create-schema=mysql --delimiter=";" --verbose Benchmark Average number of seconds to run all queries: 0.054 seconds Minimum number of seconds to run all queries: 0.047 seconds Maximum number of seconds to run all queries: 0.184 seconds Number of clients running queries: 1 Average number of queries per client: 1