Right preparation for second order closures

[gdalle]

Core

• Prepare the inner backend with the variables from inside the closure, in hvp and second_derivative

Extensions

• Add more overloads for FastDifferentiation

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 98.07692% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 93.94%. Comparing base (21a96ea) to head (b05809c).

Files	Patch %	Lines
...faceZygoteExt/DifferentiationInterfaceZygoteExt.jl	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #122      +/-   ##
==========================================
+ Coverage   92.79%   93.94%   +1.14%     
==========================================
  Files          56       56              
  Lines        1666     1733      +67     
==========================================
+ Hits         1546     1628      +82     
+ Misses        120      105      -15     

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