Add example changing mapped scalars

[banesullivan]

Users often request how to change the mapped scalars that have already been plotted. Here is a full fledged example with Trame

For #4131

[codecov]

Codecov Report

Merging #4138 (4531d5b) into main (635052d) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #4138      +/-   ##
==========================================
- Coverage   95.56%   95.56%   -0.01%     
==========================================
  Files          95       95              
  Lines       20247    20247              
==========================================
- Hits        19350    19349       -1     
- Misses        897      898       +1     

[akaszynski]

While we can't add this to the gallery, I would like for this to be rendered in our documentation somehow. We could use literalinclude or just a link, but it needs to have a "copy button". Not everyone will go source diving.

[akaszynski]

Also, is there any way we could test these? Even just a smoke test?

[banesullivan]

I can make a sphinx gallery example of similar nature to this

re: testing... yeah, this is on my to do list to figure out

[akaszynski]

I'm fine with adding this "as-is", but we should have a follow-up with testing and adding to documentation.

[banesullivan]

Merging this as is and will try to make a proper example demonstrating how to modify the mapper, prop, and lut in more ways