[gui] Change tooltip background to black
The hover-on tooltips in the web UI are hard to see, as there is too much transparency
in the grey background with lots of whites in the background.
For this reason we change the background color to black.
<template>
- <v-tooltip max-width="300" right>
+ <v-tooltip
+ max-width="300"
+ color="black"
+ right
+ >
<template v-slot:activator="{ on }">
<v-icon
color="accent"
