SNOW-3538315: add type annotations to DataFrame telemetry decorators

[gitovska]

1. Which Jira issue is this PR addressing? Make sure that there is an accompanying issue to your PR.

   Fixes SNOW-3538315

2. Fill out the following pre-review checklist:

   • I am adding a new automated test(s) to verify correctness of my new code
     • If this test skips Local Testing mode, I'm requesting review from @snowflakedb/local-testing
   • I am adding new logging messages
   • I am adding a new telemetry message
   • I am adding new credentials
   • I am adding a new dependency
   • If this is a new feature/behavior, I'm adding the Local Testing parity changes.
   • I acknowledge that I have ensured my changes to be thread-safe. Follow the link for more information: Thread-safe Developer Guidelines
   • If adding any arguments to public Snowpark APIs or creating new public Snowpark APIs, I acknowledge that I have ensured my changes include AST support. Follow the link for more information: AST Support Guidelines

3. Please describe how your code solves the related issue.

Three telemetry decorators (df_api_usage, df_to_relational_group_df_api_usage, relational_group_df_api_usage) had no type annotations, causing all wrapped DataFrame and RelationalGroupedDataFrame methods to return Unknown under strict type checkers (pyright, ty).

Added _FuncT = TypeVar("_FuncT", bound=Callable[..., Any]) and annotated all three decorators as (func: _FuncT) -> _FuncT, following the pattern used in the existing publicapi decorator in utils.py

Type annotation only. No behavioural change.

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[gitovska]

I have read the CLA Document and I hereby sign the CLA