max height & "expando" for code blocks

[RheingoldRiver]

Is your feature request related to a problem? Please describe. /kbin shows max heights for code blocks and allows you to upload extremely long snippets of code. Artemis has no such max height.

• Thread link
• Artemis screenshot courtesy of a discord user
• /kbin screenshot:

Describe the solution you'd like

• Stage 1 (high prio): a default max height on code blocks, plus an expando (please not the way kbin does it, put the expand, collapse at the top)
• Stage 2 (med-low prio): a user pref to set the max height for this (if it's easy enough to do then do it at the same time I guess)

Describe alternatives you've considered

• Skip stage 2 altogether
• Don't make an expando
• Add a copy button for code blocks (inception feature requests)

Additional context High prio cos code blocks can be truly obnoxiously long atm