PR: ipython magic command to rename tab from the console (status: dirty)

[hprodh]

Description of Changes

A small code modification adding a magic command %rename_tab.
Demo_rename_tabs.webm

There were 2 choices to be done :

• (First) There are magics commands registered in several places in spyder, I chose to register the new rename_tab in spyder/external-deps/spyder-kernels/spyder_kernels/customize/code_runner.py (alongside runfile, debugfile, profilefile, runcell, ...), simply because it did not need to create a signal and it felt simpler.
  I think it is possible to homogeneize it with the other methods especially regarding the local scope (and the @needs_local_scope decorator maybe ?). (Actually, I have a feeling I did not put it in the right place, possibly it should belong alongside %clear, %edit, etc... but I struggled figuring out the whole Ipython console <-> spyder widget pipeline...)
• (Second) (much easier) : ipython magics sends the line before it is evaluated, I chose to emulate prior evaluation with the local scope to avoid surprising results regarding the effective tab names generated.

There are some glitches regarding the tab name suffixes '/A' auto-generated, I do not consider it a major concern, yet it might need to be confirmed it is not an issue.

To be clarified

Were the added declarations in the right place ?
Can we make the automatic tab name suffixes more stable ?

Issue(s) Resolved

Provides alternative solutions to #22132 and #17415

Affirmation

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hprodh