Remove names_308_style from BrainNetworksInPython

[Islast]

• I'm ready to merge

• What's the context for this pull request?
  (this is a good place to reference any issues that this PR addresses)
  after a chat with Kirstie we've decided to remove names_308_style since it really isn't in general use.

• What's new?
  All references to names 308_style are now gone. I've run the test suite and all failures are preexisting and understood so I think it's safe to merge
  I've also thrown in some small changes to the tutorial

• What should a reviewer feedback on?
  check that 308 is the right number of rows for the residual df to have 🌺

• Does anything need to be updated after merge?
  (e.g the wiki or the WhitakerLab website)
  The documentation with the docstrings has been changed. It the other documentation will be overhauled anyway. We will need to change the wiki.

[KirstieJane]

Are you also checking the number of regions in the tutorial etc? The whitaker vertes data should have 308 regions read in 😄

There will be something somewhere that says drop the first 41 names. The way we've saved out the regional data, the names file used to have the subcortical measures at the start of the file so I had a line in the code that removed them. This is the action that we want to remove. The user can sort out their own names file!!

[Islast]

@KirstieJane I have removed all the names_308_style methods from the code (name stripping, assigning hemispheres, stripping thickness from the measures file etc). I have had to make some adjustments to the NSPN data. The residuals dataframe now has 308 columns as desired (i think?)

[KirstieJane]

That sounds great - removing "_thickness" from the MRI data is something I've wanted to do for ages 🤦‍♀️ Great to have it done here (next place is to update NSPN_rois_behavmerge.py so it doesn't happen in the first place!) I've made an issue: KirstieJane/UCHANGE_ProcessingPipeline#5