refactor: Remove backend array creation/conversion wrapper

[aturker-synnada]

Description

Closes #119

What is Changed

Include the changes introduced in this PR.

• Array creation and conversion wrappers are removed.

Checklist:

• Tests that cover the code added.
• Corresponding changes documented.
• All tests passed.
• The code linted and styled (pre-commit run --all-files has passed).

[codecov]

Codecov Report

Attention: Patch coverage is 72.46964% with 68 lines in your changes missing coverage. Please review.

Project coverage is 86.88%. Comparing base (a513e10) to head (75f53f4).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
...hril/backends/with_autograd/mlx_backend/backend.py	6.25%	30 Missing ⚠️
...hril/backends/with_autograd/jax_backend/backend.py	82.66%	13 Missing ⚠️
...il/backends/with_autograd/torch_backend/backend.py	84.21%	9 Missing ⚠️
...ithril/backends/with_autograd/mlx_backend/utils.py	11.11%	8 Missing ⚠️
mithril/backends/backend.py	58.33%	5 Missing ⚠️
...ithril/backends/with_autograd/jax_backend/utils.py	90.00%	1 Missing ⚠️
...hril/backends/with_autograd/torch_backend/utils.py	92.85%	1 Missing ⚠️
.../backends/with_manualgrad/numpy_backend/backend.py	96.77%	1 Missing ⚠️

@@            Coverage Diff             @@
##             main     #122      +/-   ##
==========================================
+ Coverage   86.72%   86.88%   +0.15%     
==========================================
  Files          61       61              
  Lines       15665    15559     -106     
==========================================
- Hits        13586    13518      -68     
+ Misses       2079     2041      -38     

Files with missing lines	Coverage Δ
...il/backends/with_manualgrad/numpy_backend/utils.py	74.40% <100.00%> (-0.60%)	⬇️
...ithril/backends/with_autograd/jax_backend/utils.py	70.52% <90.00%> (+0.46%)	⬆️
...hril/backends/with_autograd/torch_backend/utils.py	80.88% <92.85%> (-1.24%)	⬇️
.../backends/with_manualgrad/numpy_backend/backend.py	89.07% <96.77%> (+1.38%)	⬆️
mithril/backends/backend.py	64.00% <58.33%> (-0.17%)	⬇️
...ithril/backends/with_autograd/mlx_backend/utils.py	20.25% <11.11%> (+0.82%)	⬆️
...il/backends/with_autograd/torch_backend/backend.py	92.36% <84.21%> (-0.68%)	⬇️
...hril/backends/with_autograd/jax_backend/backend.py	82.86% <82.66%> (-1.25%)	⬇️
...hril/backends/with_autograd/mlx_backend/backend.py	33.33% <6.25%> (+1.54%)	⬆️