feat: Add org id support and org store link

[kristijanhusak]

This PR addresses several things:

• Adds org-store-link (Closes Add org-store-link and org-insert-link #475)
• Adds "org id" module (https://orgmode.org/manual/Handling-Links.html#FOOT28)
• Expose api for setting headline properties and ID on the headline manually

Important

Breaking change: Mapping for org-insert-link is changed from <prefix>il (<leader>oil) to <prefix>li (<leader>oli).

[Maltimore]

Could you comment on why the default mapping was changed away from <prefix>il?
I couldn't figure out what the original orgmode uses, but doesn't look to me like they use something similar to <prefix>li.
Obviously, the new mapping is not in line with all the other keymappings that insert something, so I'm sure you had a very good reason to change this!

[kristijanhusak]

I changed it to be in line with store link mapping, so to store link you do <prefix>ls as "link store" and then you do <prefix>li as "link insert". Now when I think about it, I could've probably used <prefix>sl as "store link" and leave the old mapping for insert, but I'm not sure why I went the other way.