fix: Save and decode ParsePolygon correctly

[cbaker6]

New Pull Request Checklist

• I am not disclosing a vulnerability.
• I am creating this PR in reference to an issue.

Issue Description

ParsePolygon encoding during a save and decoding resulted in (longitude, latitude) when it should be
(latitude, longitude).

Approach

When a ParsePolygon is saved, encode it as (latitude, longitude). If querying with a ParsePolygon as a constraint, encode it as (longitude, latitude). Always decode a ParsePolygon as (latitude, longitude).

If a developer used ParseSwift <= 5.7.1 to save/update ParsePolygon's, they will need to update the respective ParseObject's by swapping the latitude and longitude manually.

Deprecated withinPolygon() query constraint for geoPoint() and polygonContains() for polygon()

TODOs before merging

• Add tests
• Add entry to changelog
• Add changes to documentation (guides, repository pages, in-code descriptions)

[codecov]

Codecov Report

Merging #118 (5e8e03b) into main (7f07262) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #118   +/-   ##
=======================================
  Coverage   91.57%   91.58%           
=======================================
  Files         173      173           
  Lines       15409    15425   +16     
=======================================
+ Hits        14111    14127   +16     
  Misses       1298     1298           

Impacted Files	Coverage Δ
Sources/ParseSwift/Types/ParsePolygon.swift	97.84% <100.00%> (+0.12%)	⬆️
Sources/ParseSwift/Types/QueryConstraint.swift	100.00% <100.00%> (ø)

... and 2 files with indirect coverage changes