Dataset CLI tool to find duplicates

[Ariana-B]

Reason for this pull request

Easily scan the database for duplicate indexed datasets, identifying duplicates by a set of specified field values, and produce a report on any datasets found.

Proposed changes

• New dataset CLI tool, find-duplicates that takes in fields by which to search for duplicates and optional products in which to search

• Add expression_with_leniency property to DateRangeDocField to extend date range by +-500ms

• Closes #xxxx

• Tests added / passed

• Fully documented, including docs/about/whats_new.rst for all changes

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📚 Documentation preview 📚: https://datacube-core--1517.org.readthedocs.build/en/1517/

[SpacemanPaul]

As discussed on Teams:

You have in sql agdc.common_timestamp( str-value-from-json )::timestamp

common_timestamp returns a timestamp with timezone, then casting to timestamp with ::timestamp returns a timestamp WITHOUT timezone by IGNORING the timezone.

I think we need to explicitly convert to UTC, probably with the AT TIME ZONE operator. (Or to the system time zone? But that would complicate testing)

(Classic gotcha - virtually never what any real world user would actually want, and contrary to the SQL standard.)

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (9fb8c8c) 91.75% compared to head (94d6a5b) 91.79%.
Report is 2 commits behind head on develop.

Files	Patch %	Lines
datacube/index/memory/_datasets.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1517      +/-   ##
===========================================
+ Coverage    91.75%   91.79%   +0.03%     
===========================================
  Files          132      132              
  Lines        14552    14617      +65     
===========================================
+ Hits         13352    13417      +65     
  Misses        1200     1200              

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[SpacemanPaul]

I'm going to be a pain and ask you to update the memory index driver implementation as well - should be heaps easier than the ones that use a database.