Apply `ctx` abbreviation consistently

[huong-li-nguyen]

Description

• Small clean-up PR to use ctx instead of callback_context consistently to be less verbose and use official abbreviations, see here

Note: ctx shortcut currently doesn't exist for dash_clientside yet, so there we would use the old syntax. However, with this recent PR on Dash that got merged (but not released), we should be able to replace something like:

window.dash_clientside.callback_context.triggered[0].prop_id.split('.')[0] with window.dash_clientside.callback_context.trigger_id in the future if we upgrade to the latest Dash version

Screenshot

Notice

• [x] I acknowledge and agree that, by checking this box and clicking "Submit Pull Request":

  • I submit this contribution under the Apache 2.0 license and represent that I am entitled to do so on behalf of myself, my employer, or relevant third parties, as applicable.
  • I certify that (a) this contribution is my original creation and / or (b) to the extent it is not my original creation, I am authorized to submit this contribution on behalf of the original creator(s) or their licensees.
  • I certify that the use of this contribution as authorized by the Apache 2.0 license does not violate the intellectual property rights of anyone else.
  • I have not referenced individuals, products or companies in any commits, directly or indirectly.
  • I have not added data or restricted code in any commits, directly or indirectly.