Expand IcebergIO write API to cover all write options

[clairemcginty]

Expands iceberg write API to support

• sort order
• partition spec
• arbitrary other options you want to pass to the ManagedIO config map, ie. distribution_mode

• Renames configProperties to writeProperties to match Iceberg convention https://iceberg.apache.org/docs/latest/configuration/#write-properties

[clairemcginty]

I thought this was more flexible than adding a dedicated named param for every new option added to the Iceberg write api (i.e. distribution_mode, autosharing, etc...)

[regadas]

Yeah might be better this way indeed till the API stabilizes

[codecov]

Codecov Report

❌ Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 61.99%. Comparing base (3b35141) to head (c1958b1).

Files with missing lines	Patch %	Lines
...ain/scala/com/spotify/scio/iceberg/IcebergIO.scala	85.71%	1 Missing ⚠️
...scio/iceberg/syntax/IcebergSCollectionSyntax.scala	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5986   +/-   ##
=======================================
  Coverage   61.99%   61.99%           
=======================================
  Files         323      323           
  Lines       11737    11742    +5     
  Branches      793      829   +36     
=======================================
+ Hits         7276     7280    +4     
- Misses       4461     4462    +1     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[clairemcginty]

This won't work until the next Beam release w/ apache/beam#39250 ; I did validate that this test passes when using a locally built Beam snapshot 👍