Correctly order earliest / latest for Ambiguous times in local TimeZone

[AVee]

This swaps earliest / latest in Local Timezone handling as it seems to be consistently in the incorrect order, see issue #1625 . I think I changed all places where an instance of MappedLocalTime::Ambiguous is created in the unix part of offset/local. I haven't yet looked at Windows.

I've also added some tests to cover this, which should cover most cases.

[codecov]

Codecov Report

Attention: Patch coverage is 99.35897% with 2 lines in your changes missing coverage. Please review.

Project coverage is 91.77%. Comparing base (7974c60) to head (48d1c65).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/offset/local/tz_info/rule.rs	75.00%	1 Missing ⚠️
src/offset/local/tz_info/timezone.rs	99.67%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1626      +/-   ##
==========================================
+ Coverage   91.12%   91.77%   +0.65%     
==========================================
  Files          37       37              
  Lines       17137    17443     +306     
==========================================
+ Hits        15616    16009     +393     
+ Misses       1521     1434      -87     

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[djc]

Thanks for working on this, the code changes look good and I appreciate the added test coverage.

[djc]

These big binary blobs are a pain to manage. What value does this test have over and above the test_dst_backward_posix_tz tests? Do these tests actually gain us any coverage?