Sparse SVD

[dallan-keylogic]

Summary/Motivation:

Presently, the SVDToolbox isn't widely utilized, in part because of the limited options for calculating the SVD. Scipy's dense SVD is time-consuming on problems larger than 1000x1000, while its sparse SVD does not work well to find the singular values of the smallest magnitude.

Therefore, I've implemented a custom version of the SVD that is based on Rayleigh-Ritz iteration.

I'd appreciate testers for this method before we merge it.

Legal Acknowledgement

By contributing to this software project, I agree to the following terms and conditions for my contribution:

1. I agree my contributions are submitted under the license terms described in the LICENSE.txt file at the top level of this directory.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

[codecov]

Codecov Report

Attention: Patch coverage is 90.32258% with 12 lines in your changes missing coverage. Please review.

Project coverage is 76.87%. Comparing base (6e72af3) to head (1ec214f).

Files with missing lines	Patch %	Lines
idaes/core/util/linalg.py	91.45%	7 Missing and 3 partials ⚠️
idaes/core/util/model_diagnostics.py	71.42%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1566      +/-   ##
==========================================
+ Coverage   76.85%   76.87%   +0.02%     
==========================================
  Files         394      395       +1     
  Lines       63241    63365     +124     
  Branches    10359    10382      +23     
==========================================
+ Hits        48604    48713     +109     
- Misses      12188    12200      +12     
- Partials     2449     2452       +3     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[dallan-keylogic]

Pylint is complaining about "Possible unbalanced tuple unpacking". The source of the issue is that the function returns three variables, U, svals, and V, if m=n but it additionally returns a basis for the (left) null space if m!=n. There are multiple ways to make this warning go away, but I want some feedback about the return signature of the function. Should I always return the null space, or only if a specific option is included?