Massively decrease statusline configuration

Before this I had a lot of junk in my statusline configuration that was
overly complicated and unnecessary. Since I previously used vim-airline
I was used to having the mode on the far left of the statusline. I
realized that I never actually looked at that, so I'd rather just look
at the same mode that shows up in the command line. The only difference
being the lack of color for a visual cue. I feel like I normally know
what mode I'm in so I don't really care. I also feel like if I don't
know what mode I'm in I just mash <Esc> till I'm back in normal mode.
Those custom modes and colors were the bulk of the code in this previous
configuration.