Selector serialization

[zhanyuanucb]

This PR fixes asyml#499 (comment)

Description of changes

• Included Configurable and relevant changes from Forte master branch
• Selector inherits from Configurable and adapts new __init__ signature.
• Assured NameMatchSelector and RegexNameMatchSelector are backward compatible
• Slightly changed in Forte pipeline deserialization to instantiate a selector from configs

Possible influences of this PR.

For backward compatibility, the __init__ of NameMatchSelector and RegexNameMatchSelector are now more generic, taking arguments *args and **kwargs. Not sure whether this will cause some problems.

Test Conducted

In tests/forte/data/selector_test.py, added test_name_match_selector_backward_compatability and test_regex_name_match_selector_backward_compatability to test backward compatibility of these two selectos.