feature: show tooltip titles on touch screens

[Flix6x]

Description

• Adds the touched class to the html body, allowing custom css for touchscreens.
• Show tooltips on touchscreens, based on the title attribute of html elements.
• I added this as core FM functionality in base.html so plugins can use it, too (this was my primary concern).

Look & Feel

How to test

ngrok http 5000

Use your phone to visit pages with tooltips, such as table items on the /users, /assets and /asset/<id> pages.