[feat] Flagr front UI should auto focus the search bar

[wildefires]

Expected Behavior

Because the search bar is the most common use for people, it should be automatically highlighted so users don't have to click into it to begin to search

Current Behavior

Does not autofocus

Possible Solution

Change to the main.js and Flags.vue files to add an autofocus

Context

Basically just extra clicks. I don't like using my mouse :)