PR 1894, LB-1373: Postgres date time precision tests.

[XDelphiGrl]

This test adds validation of data type precision for Postgres time and time with timezone datatypes.

• replaced the 'invalid test' expected sql file with actual sql
• deleted extraneous datatypes.datetime.json files from several Postgres version subdirectories
• updated the datatypes.datetime.json file at the root of /postgres with expected JSON snapshot output.

NOTE

• There is a bug related to the interval Postgres time datatype. The changesets in the XML changelog are commented out with a link back to the open PR to address that issue. When we do address issue, the test will need to be updated.

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Must merge after GH PR 1894 for liquibase/liquibase merges to master!

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GH PR for liquibase/liquibase
Internal Jira Ticket

[KushnirykOleh]

Not part of 4.8.0, waiting for next release