Replace 'popper.js' with 'floating-vue' for tooltip components

[BeneRichi]

We upgraded to Vue3, and some packages like popper.js are no longer compatible. We haven't updated this particular case in the styleguide yet.

Please replace popper.js with [floating-vue](https://floating-ui.com/) in the styleguide, and also update the implementation of components where popper.js was used before e.g c-tooltip.

Here's a commit example of the recent implementation with floating-vue.