[ITensorMPS] Make ITensorTDVP functions into compatibility layer

[emstoudenmire]

This PR changes the names of the interface functions moved from ITensorTDVP. Now they are prepended with itensortdvp_ so as to be a compatibility layer behind which we can translate arguments to be able to work on the ITensorMPS.alternating_update code however we want without breaking ITensorTDVP.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 20 lines in your changes are missing coverage. Please review.

Project coverage is 50.30%. Comparing base (f06d5c7) to head (dc4d504).

❗ Current head dc4d504 differs from pull request most recent head 3fc6cbc. Consider uploading reports for the commit 3fc6cbc to get more accurate results

Files	Patch %	Lines
src/ITensorMPS/tdvp.jl	0.00%	12 Missing ⚠️
src/ITensorMPS/update_observer.jl	0.00%	3 Missing ⚠️
src/ITensorMPS/contract_mpo_mps.jl	0.00%	1 Missing ⚠️
src/ITensorMPS/dmrg.jl	0.00%	1 Missing ⚠️
src/ITensorMPS/dmrg_x.jl	0.00%	1 Missing ⚠️
src/ITensorMPS/linsolve.jl	0.00%	1 Missing ⚠️
src/ITensorMPS/sweep_update.jl	0.00%	1 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1371      +/-   ##
==========================================
- Coverage   57.58%   50.30%   -7.28%     
==========================================
  Files         114      113       -1     
  Lines        9004     8965      -39     
==========================================
- Hits         5185     4510     -675     
- Misses       3819     4455     +636     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[mtfishman]

@emstoudenmire I also see this warning:

WARNING: Method definition update!(ITensors.ITensorMPS.AbstractObserver) in module ITensorMPS at /Users/mfishman/.julia/packages/ITensors/jmIjr/src/ITensorMPS/update_observer.jl:3 overwritten in module ITensorTDVP at /Users/mfishman/.julia/dev/ITensorTDVP/src/update_observer.jl:4.

because of the overload here: https://github.com/ITensor/ITensors.jl/blob/v0.3.60/src/ITensorMPS/update_observer.jl.

Let's just remove that for now and decide how update! will work in a future PR.

Removing that overload aligns with the plan of moving the Observers.jl dependency to a package extension anyway, since that will likely be implemented by defining a new function (say called ITensorMPS.update_observer!) which will be used in alternating_update and can be overloaded on Observers.Observer (in an ITensorsObserversExt package extension) and ITensorMPS.AbstractObserver.

EDIT: We could already start that process here, by defining an interface function ITensorMPS.update_observer! with an empty definition, and overload it for ITensorMPS.AbstractObserver. Then when we make ITensorsObserversExt in a future PR it can just overload ITensorMPS.update_observer! on Observers.Observer.

[mtfishman]

[test ITensorMPS][test ITensorGaussianMPS]

[github-actions]

Run ITensorGaussianMPS tests from comment trigger: succeeded ✅
https://github.com/ITensor/ITensors.jl/actions/runs/8528892800

[github-actions]

Run ITensorGaussianMPS tests from comment trigger: succeeded ✅
https://github.com/ITensor/ITensors.jl/actions/runs/8528892800

[github-actions]

Run ITensorMPS tests from comment trigger: succeeded ✅
https://github.com/ITensor/ITensors.jl/actions/runs/8528892802

[github-actions]

Run ITensorMPS tests from comment trigger: succeeded ✅
https://github.com/ITensor/ITensors.jl/actions/runs/8528892802