upgrade to nuxt3 / vue3/ vite

The ecosystem with which Gancio is developed carries a not inconsiderable technical debt.

The stack used is based on Nuxt2, Vue2 and Vuetify2, projects that have reached EOL as of December 31, 2023.

In addition many of the sub-dependencies have aged over time and in fact installing the software there is a large list of warnings such as "This package is no longer supported" or "This package has reached EOL.".

In complex projects it is not trivial to update dependencies, especially when there are big breaking changes as in the case of nuxt3, vue3 and vuetify3 which on some architectural aspects have definitely changed their approach to improve performance, ease of development and maintenance.

In addition to removing the technical debt and decreasing the number of external dependencies this would allow a nice refactoring by clearly dividing the responsibilities into more modular code.

Will be a bloodbath, especially maintaining backward compatibility :D

This will take me the next 2/3 month so please do not expect new feature in the next period.