Extend Silo with quadratic elements

[cessenat]

Adding quadratic elements for VisIt 3.4RC as already done for develop

Description

Adds quadratic elements to 3.4RC as it is already done in develop

Added the quadratic constants that shall later be in a coming Silo release

Type of change

• Bug fix~~
• New feature~~
• Documentation update~~
• Other~~

How Has This Been Tested?

Reminders:

• Please follow the style guidelines of this project.
• Please perform a self-review of your code before submitting a PR and asking others to review it.
• Please assign reviewers (see VisIt's PR procedures for more information).
  Could @markcmiller86 review that PR which is alike "feat-cessenat-04may24-silo-add-quadratic" see:
  https://github.com/visit-dav/visit/pull/19491/files

Checklist:

• I have commented my code where applicable.~~
• I have updated the release notes.~~
• I have made corresponding changes to the documentation.~~
• I have added debugging support to my changes.~~
• I have added tests that prove my fix is effective or that my feature works.~~
• I have confirmed new and existing unit tests pass locally with my changes.~~
• I have added new baselines for any new tests to the repo.~~
• I have NOT made any changes to protocol or public interfaces in an RC branch.~~