Several static utility methods in SimpleJdbcTestUtils accept an instance
of SimpleJdbcTemplate as an argument; however, SimpleJdbcTemplate has
been deprecated since Spring 3.1 in favor of simply using JdbcTemplate
which now also supports Java 5 language constructs such as var-args.
Consequently, use of such methods from SimpleJdbcTestUtils results in
deprecation warnings without an equivalent API to migrate to.

This commit addresses this issue by migrating all existing methods in
SimpleJdbcTestUtils to JdbcTestUtils. The migrated methods now accept an
instance of JdbcTemplate as an argument, thereby avoiding the
deprecation warnings but maintaining semantic compatibility with the
functionality previous available in SimpleJdbcTestUtils.

In addition, this commit also introduces two new methods:

 - countRowsInTableWhere(): counts the rows in a given table, using
   a provided `WHERE` clause
 - dropTables(): drops the tables with the specified names

Issue: SPR-9235