fix(winbar): clean winbar value input

[khaneliman]

Resolve issue with file names with characters that can break logic. Tried keeping diff smaller, not sure if we need to check for a value before doing the transform, or not like I have in personal patch khaneliman/khanelivim@ab9164a

vim.schedule callback: ...k/myNeovimPackages/opt/glance.nvim/lua/glance/winbar.lua:0: E539: Illegal character <A>
stack traceback:
	[C]: in function 'nvim_win_set_option'
	...k/myNeovimPackages/opt/glance.nvim/lua/glance/winbar.lua: in function <...k/myNeovimPackages/opt/glance.nvim/lua/glance/winbar.lua:0>

Example currently (error thrown, no file name):

Example value when patched: