The ability to modify single cell properties during the simulation run

[WeinaJi]

Context

Scope

Testing

Review

• PR description is complete
• Coding style (imports, function length, New functions, classes or files) are good
• Unit/Scientific test added
• Updated Readme, in-code, developer documentation

[bbpbuildbot]

Logfiles from GitLab pipeline #236288 (:no_entry:) have been uploaded here!

Status and direct links:

• ✅ docs
• ⛔ test-unit
• ⛔ test-integration
• ⛔ test-integration-e2e
• ⛔ test-scientific
• ⛔ test-scientific-ngv
• ✅ set_alt_branches
• ⏩ build-package
• ⏩ publish-package
• ⏩ publish-docs

[WeinaJi]

I am closing this PR because it is not ready.
One issue is about the CoreNEURON reporting where we would like to have one report for all subprocesses 0->t1, t1->t2, t2->tstop. With this change, we could create a report from 0->tstop at the 1st subprocess, and update it in the following subprocesses. However, it conflicts with the major usecase (one single run 0->tstop) where users may ask longer reporting time than the simulation time in the config file and we still create a report up to the simulation time.