Support multiple measurements and shot vectors in `param_shift(... broadcast=True)`

[dwierichs]

Context: Shot vectors and multiple measurements are currently explicitly not supported when using param_shift with the broadcast=True option.

In #5666 , a crucial subroutine _evaluat_gradient is being prepared to allow for support of these scenarios.

Description of the Change: Allow for shot vectors and/or multiple measurements in param_shift(..., broadcast=true). Due to the changes in #5666 including unit tests for the relevant subroutines, this PR mostly is concerned with integration tests.

Benefits: Feature parity with broadcast=False, allowing faster gradient evaluation.

Possible Drawbacks:

Related GitHub Issues: fixes #5598

[sc-62283]

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.67%. Comparing base (9b3060f) to head (d2a6689). Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5667      +/-   ##
==========================================
- Coverage   99.67%   99.67%   -0.01%     
==========================================
  Files         421      421              
  Lines       40189    39872     -317     
==========================================
- Hits        40060    39742     -318     
- Misses        129      130       +1     

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