Toggle between oob and legacy invitations

[TimoGlastra]

See #87 for general context

1. Add useLegacyInvitations boolean type to the connectionSlice.ts. True should be the default
2. add setUseLegacyInvitations to the reducers in the connections slice that sets wheter to use legacy invitations on the state.
3. Add option "Change Connection Invitation Type" with options "Legacy (RFC 0160)" and "Out Of Band" to the KBar.tsx file.
4. (ideally) add a way to see if we're using legacy / oob invitation from kbar (timc1/kbar)
5. Whenever we create an invitation we should call /oob/create-legacy-invitation if legacy is enabled, and /oob/create-invitation otherwise. In both cases we should use the return invitaiton url and encode is as a QR (as is already happening)

[janrtvld]

For number 4: maybe a checkmark to indicate the type that is active? Like this: