Removed Microsecond from Extract function

[shigarg1]

Description

This PR

1. Removes microsecond as supported unit for EXTRACT function. Currently the function is returning epoch(in secs)/1000 which is incorrect.
2. TIME_EXTRACT function can also supports MILLISECOND as the unit. Updated the docs.

Query - SELECT TIME_EXTRACT(CAST('2013-10-07 12:13:27.123457' AS TIMESTAMP), 'MILLISECOND')
Result - 123 // Expected

This change was added as part of ea4bad7

Bug

Query1 - SELECT EXTRACT(MILLISECOND FROM CAST('2013-10-07 12:13:27.123457' AS TIMESTAMP))
Result - 123 // Expected

Query2 - SELECT EXTRACT(MICROSECOND FROM CAST('2013-10-07 12:13:27.123456' AS TIMESTAMP))
Result - 1,381,148 // **Incorrect**. Correct value should be 123456

NOTE: Currently joda-time only supports millisecond precision. As of java8 release it a general recommendation to move from joda-time to new date and time API found in the java.time package.

[shigarg1]

@kgyrtkirk Can you please help to review this. I came across this while exploring Druid.

I also want to know if there is a reason to still use joda-time ? It is generally recommended to migrate to java time since Java8. If you want I can look at the feasibility of migrating from joda-time to java time.

[kgyrtkirk]

🤦 it was clearly wrong; 695 ms and 946723 microsec...

[kgyrtkirk]

we could possibly migrate to java.time but these joda time things will be present at a lot of places.... Bounds/Ranges/Filtration