Move most cookies to LocalStorage

[JuHardtung]

Most cookies like vuetifyTheme, currentActivity, currentPlace and others don't have to be saved as cookies. LocalStorage works better for those, as LocalStorage is more persistent. Especially when the user has cookies disabled in the browser and/or clears them on a regular basis.

We should only really need the authentication token in cookies, which has to be sent in each header to the backend.

[JuHardtung]

Commit 089f87f39b324d9fbc28729e8e3bb911b2e64e73 laid the groundwork for this. Now we can save data to localStorare which persists even after reloading or closing the browser.

I'll list the remaining cookies that should be moved to localStorage here:

• [x] placeModulesPreset
• [x] posModulesPreset
• [x] initDone
• [x] showAllPlaceInfo
• [x] showAllPosInfo
• [x] (currentActivity)
• [x] (currentPlace)
• [x] (currentPosition)

And other settings that should persist after reloading/relaunching the fieldbook:

• [x] vuetify theme (dark/light)
• [x] language settings
• [x] logged in account (you get automatically logged out after reload of the fieldbook, but this might just be a bug)

[JuHardtung]

Commit 1b3eb2ee2baa6ff9fa1d659c130c88028b50b8fc moved the last functionality from cookies to the persistent localStorage.

Cookies are now only used for the JWT, which is needed for account management and should not be persistently saved in localStorage.