Add (check) full support for sampling in full parity with Lightning.

[LuisAlfredoNu]

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---

Context:
Migrate LightningGPU to the new device API

Description of the Change:
Add all the functionality of the new device API to LGPU.

Benefits:

Possible Drawbacks:

Related GitHub Issues:

Freezzed PR ⚠️ ❄️

To make a smooth integration of LightningGPU with the new device API, we set the branch gpuNewAPI_backend as the base branch target for future developments related to this big task.

The branch gpuNewAPI_backend has the mock of all classes and methods necessary for the new API. Also, several tests were disabled with

if device_name == "lightning.gpu":
    pytest.skip("LGPU new API in WIP.  Skipping.",allow_module_level=True)

However, these tests will unblocked as the implementation progresses.

After all the developments for integrating LightningGPU with the new API have been completed then the PR will be open to merge to master

[sc-70946]

[github-actions]

Hello. You may have forgotten to update the changelog!
Please edit .github/CHANGELOG.md with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.

[codecov]

Codecov Report

Attention: Patch coverage is 9.63855% with 75 lines in your changes missing coverage. Please review.

Project coverage is 56.16%. Comparing base (a7c4b09) to head (f63a234).
Report is 1 commits behind head on gpuNewAPI_backend.

Files with missing lines	Patch %	Lines
pennylane_lightning/lightning_gpu/lightning_gpu.py	9.63%	75 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (a7c4b09) and HEAD (f63a234). Click for more details.

HEAD has 3 uploads less than BASE

Flag	BASE (a7c4b09)	HEAD (f63a234)
	9	6

Additional details and impacted files

@@                  Coverage Diff                   @@
##           gpuNewAPI_backend     #908       +/-   ##
======================================================
- Coverage              93.77%   56.16%   -37.61%     
======================================================
  Files                    110       28       -82     
  Lines                  13968     2345    -11623     
======================================================
- Hits                   13098     1317    -11781     
- Misses                   870     1028      +158     

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[AmintorDusko]

Looks good!

[maliasadi]

Nice work @LuisAlfredoNu!