Make "Show template" option persistent

[annezazu]

Right now, due to this change, the template is shown by default when editing pages. Alongside this, is a "show template" option that can be toggled on/off. Currently, if you enter a page, turn off the template, and then leave and return the show template option doesn't persist. I think making it persistent will happen lessen future feedback I'm expected from this change as folks could opt out once and move on.

[yogeshbhutkar]

I’d like to delve deeper into this enhancement. Setting this value in the preferences store seems like a solid approach. I’ll be submitting a PR to implement this soon.

[Mamaduka]

I don't think another persistent option is a solution here, and a feature introduced via #62304 can be opted out. Smart defaults should be preferred over the software options.

Let's avoid patching any editor behavior that is not final. Please look at the ongoing discussion in #62304 and #67867.