feat: Add multi-label selection and Table metadata extraction

[NathanZlion]

Issue #, if available:

ybbPAl2KONnZ

• Add LabelSelectionMode ('single' | 'multi') and extend analytics label handling to support multi-element label extraction, by treating metadata keys that end with "labels" as multi-labels; preserve "label" for single-labels.
• Add table-specific metadata extraction when local metadata identifies an awsui.Table: properties.columnLabels, properties.selectedItemsLabels

Description of changes:

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.05%. Comparing base (c09d82c) to head (c6deda9).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #182      +/-   ##
==========================================
+ Coverage   99.00%   99.05%   +0.05%     
==========================================
  Files          42       42              
  Lines        1101     1165      +64     
  Branches      280      319      +39     
==========================================
+ Hits         1090     1154      +64     
+ Misses         11       10       -1     
- Partials        0        1       +1     

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[gethinwebster]

I think splitting this code into a new method would make more sense: currently it's within processSingleLabel which is a bit confusing

[gethinwebster]

maybe even processLabel should be split into two methods too, overall I think it would make the code flow and typings more clear