Is your feature request related to a problem? Please describe.
I always tend to look/import some of my older auras in order copy parts of code from it which can be a time consuming process.

Describe the solution you'd like
After opening a code block, you have the option to save the entire code block's content or only the highlighted parts (once blizz fixes it, ffs), then a new window appears where you can specifiy its name.

And another button within the code block for "Insert code from snippet" or w/e where you can search for snippets.

And a new saved variable for snippets? WeakAurasSnippets 💯

There are a few addons dedicated to save snippets of lua code
wowlua https://www.wowinterface.com/downloads/info7366-WowLua.html
REHack https://www.wowinterface.com/downloads/info24734-REHack-UINotebook.html

I think that's out of scope.