Update Vue3 and tooling

[SamR1]

TODO:

• upgrade Vue to 3.2.x to 3.3.x
• change tools (Vue CLI is now in maintenance mode):
  • tooling: replace vue-cli with Vite
  • unit-tests: replace chai & mocha with Vitest

The library for state managament will be changed later (see #454)

[SamR1]

released in v0.7.26