feature info support for WMTS imagery provider

[ShubhamSharmaFAO]

Feature: WebMapTileService GetFeatureInfo support & specs

Description

Adds WMTS GetFeatureInfo (feature picking) to WebMapTileServiceImageryProvider:

• New options: enablePickFeatures (default true), getFeatureInfoFormats, getFeatureInfoUrl, getFeatureInfoParameters.
• Implements pickFeatures via UrlTemplateImageryProvider + GetFeatureInfoFormat; supports both KVP and REST templating.
• Honors dimensions and time-dynamic values; supports JSON/XML/HTML with format fallback.
• Non‑breaking: default behavior enables picking; existing imagery fetching unchanged.
• Provides GetFeatureInfo for WMTS imagery layers.

Issue number and link

• Discussion: https://github.com/TerriaJS/terriajs/discussions/7603

Testing plan

• Lint/build/docs/types

npm run eslint
npm run build
npm run build-docs
npm run build-ts

• Targeted unit suite

npm run test -- --includeName WebMapTileServiceImageryProvider

• Verifies:
  • Disabled states: empty getFeatureInfoFormats, enablePickFeatures=false
  • Initialization for KVP and REST URLs
  • getFeatureInfoUrl override used for picking
  • Request construction (service/version/request/layer/style/tilematrixset/tilematrix/tilecol/tilerow/i/j/infoformat)
  • Dimensions in KVP (query) and REST (template) forms
  • Time-dynamic values in query and template (with URL-encoding)
  • getFeatureInfoParameters lowercased into query
  • JSON parsing to ImageryLayerFeatureInfo[] with name/position checks
  • XML (fetchXML) and HTML (fetchText) infoformats
  • Fallback to next format when the first request fails

Author checklist

• I have submitted a Contributor License Agreement
• I have added my name to CONTRIBUTORS.md
• I have updated CHANGES.md with a short summary of my change
• I have added or updated unit tests to ensure consistent code coverage
• I have updated the inline documentation, and included code examples where relevant
• I have performed a self-review of my code