Add tf.regex_match for regex match support (#19160)

Add tf.regex_match for regex match support (#19160)

* Add tf.regex_match for regex match support

This fix tries to address the issue raised in 18264.
Currently tf.regex_replace has already been supported
though there was no regex match support.
This fix adds the tf.regex_match support in a similiar
pattern as tf.regex_replace.

This fix fixes 18264.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
* Update BUILD file for the tf.regex_match kernel

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

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
* Add test cases for tf.regex_match

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

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

update with:
```
bazel-bin/tensorflow/tools/api/tests/api_compatibility_test
           --update_goldens True
```

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
* Expose regex_full_match in tf.strings namespace

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

```
bazel-bin/tensorflow/tools/api/tests/api_compatibility_test
           --update_goldens True
```

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