feat(router): add options to convertToParamMap - #70128

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/angular/angular/blob/main/contributing-docs/commit-message-guidelines.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• angular.dev application / infrastructure changes
• Other... Please describe:

What is the current behavior?

There is currently no way to configure options like case-insensitive key lookups without manually transforming the input parameters object.

Issue Number: #55968

What is the new behavior?

convertToParamMap now accepts an optional second argument options?: ParamMapOptions:

• Introduces ParamMapOptions interface with a caseInsensitive?: boolean property.
• When caseInsensitive: true is provided, parameter key lookups (get, getAll, has, keys) behave in a case-insensitive manner.
• Default behavior remains backwards compatible and case-sensitive when options are omitted.

Does this PR introduce a breaking change?

• Yes
• No

Other information