feat: add DashboardContextEnricher pipeline step for student dashboard filter

[pwnage101]

Jira: ENT-11569

Summary:
A DashboardContextEnricher pipeline step is defined in enterprise/filters/dashboard.py and injects all enterprise dashboard context keys (enterprise_message, consent_required_courses, is_enterprise_user, and enterprise portal keys). Unit tests cover the pipeline step with enterprise and non-enterprise users.

[pwnage101]

Note for implementer: add openedx-filters to requirements.

[codecov]

Codecov Report

❌ Patch coverage is 96.77419% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 85.93%. Comparing base (79fb87c) to head (972b1d0).

Files with missing lines	Patch %	Lines
enterprise/filters/dashboard.py	96.77%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2552      +/-   ##
==========================================
+ Coverage   85.91%   85.93%   +0.02%     
==========================================
  Files         250      251       +1     
  Lines       16604    16635      +31     
  Branches     1639     1640       +1     
==========================================
+ Hits        14266    14296      +30     
- Misses       2001     2002       +1     
  Partials      337      337              

Flag	Coverage Δ
unittests	85.93% <96.77%> (+0.02%)	⬆️

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[pwnage101]

AI added these exception handlers, but I'm not really a fan of them. If we didn't catch exceptions before, let's not just randomly start doing it, especially if we don't even know the specific exception and are forced to disable broad-except which is a bad code smell. Furthermore, swallowing the exception is probably extra bad for visibility of regressions during local/stage testing.

[pwnage101]

Nit: I feel like the function signature should have type hints, at least the inputs for now:

Suggested change

	def run_filter(self, context, template_name): # pylint: disable=arguments-differ
	def run_filter(self, context: dict[str, Any], template_name: str): # pylint: disable=arguments-differ

Just copy the types from the filter itself: https://github.com/openedx/openedx-filters/blob/d517006b0f61050f027de90459e50e2745825992/openedx_filters/learning/filters.py#L829C34-L829C48