Add uint32 and uint64 support with tf.train.batch (#18805)

* Add uint32 and uint64 support with tf.train.batch

This fix tries to address the issue raised in 18586
to have uint32 and uint64 support with tf.train.batch.

This fix add uint32 and uint64 to `CopyElementToSlice`
for the support.

This fix fixes 18586.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Add test case for uint32 with tf.train.batch

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Add uint64 test case

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>