admin/ui updates:

[dcarbone]

• updating jquery to 3.6.0
• updating materialize to 1.0.0
• updating material icons to 4.0.0
• adding go generate makefile target
• adding go generate target to build target
• adding admin cleaning target
• removing assets from git, they will be fetched at build

[CLAassistant]

All committers have signed the CLA.

[nathanejohnson]

I had to rebase this off of master to get it to compile on my mac with 1.18, I also went through the Makefile and made some tweaks.