Make browser account sync optional

[olfek]

Describe the issue

Some people, like myself for example, may not want to sync data with the browser account.

Browser

Firefox

Browser Version

117.0.1 (64-bit)

Extension Version

6.3.5

[mymindstorm]

Switch storage to local in settings and it will not sync.

[olfek]

@mymindstorm is it local by default?

[olfek]

just checked, doesn't look like it, I think browser sync should be off by default