Add to_string method for GeoValue

[AnneYang720]

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Description of change

Add to_string method for GeoValue. The lack of to_string will cause NotImplementedError when building query string from Nodes.

[codecov-commenter]

Codecov Report

Base: 78.91% // Head: 92.02% // Increases project coverage by +13.11% 🎉

Coverage data is based on head (1a59d5a) compared to base (4200d54).
Patch coverage: 0.00% of modified lines in pull request are covered.

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #2404       +/-   ##
===========================================
+ Coverage   78.91%   92.02%   +13.11%     
===========================================
  Files         110      110               
  Lines       28735    28737        +2     
===========================================
+ Hits        22675    26446     +3771     
+ Misses       6060     2291     -3769     

Impacted Files	Coverage Δ
redis/commands/search/querystring.py	0.00% <0.00%> (ø)
tests/test_asyncio/test_search.py	98.26% <0.00%> (-0.35%)	⬇️
redis/commands/core.py	82.17% <0.00%> (+0.16%)	⬆️
redis/asyncio/client.py	92.22% <0.00%> (+0.17%)	⬆️
tests/test_commands.py	89.92% <0.00%> (+0.18%)	⬆️
tests/test_json.py	100.00% <0.00%> (+0.19%)	⬆️
tests/test_asyncio/test_json.py	100.00% <0.00%> (+0.24%)	⬆️
redis/connection.py	86.30% <0.00%> (+0.48%)	⬆️
tests/test_lock.py	100.00% <0.00%> (+0.49%)	⬆️
tests/test_asyncio/test_lock.py	100.00% <0.00%> (+0.52%)	⬆️
... and 23 more

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[akx]

This would be more succinct as an f-string:

Suggested change

	return "[{0} {1} {2} {3}]".format(
	self.lon,
	self.lat,
	self.radius,
	self.unit
	)
	return f"[{self.lon} {self.lat} {self.radius} {self.unit}]"