Add basic activity log

[dcbr]

This PR adds a basic implementation for an activity log in each group. Currently 4 types of activity are logged: updating the group settings and creating/updating/deleting an expense. If an active user is configured, the activity message includes the name of that active user. If #95 is approved, the "infinite scroll" feature can also be applied to this activity log (the implementation here is derived from the expense list).

Related issues are #15, #103 and #106.

[ChristopherJohnston]

nice! Might also be good to have the activity history for an individual expense at the bottom of the edit expense page.

Also a +1 on getting the #95 infinite scroll PR merged!

[justcallmelarry]

Could be nice if the expenses were links to the expense in question!

[dcbr]

@justcallmelarry They actually are linking to the expense, as long as it was not deleted in the meantime. This is denoted by the small arrows on the right (and a pointer cursor while hovering).

[justcallmelarry]

@dcbr ah ok! nice! was not clear from the screenshot for me 😅 i was looking for the name of the group to be a link or similar

[justcallmelarry]

This would also benefit from soft-deleting expenses, so that you can un-delete the expense from the log!

[dcbr]

@justcallmelarry Yes indeed! However, I didn't want to introduce too many changes here, and just introduce a basic version that can later be extended. But I agree soft-deletion would be a nice feature for a follow-up PR :)

[sh3hz]

Hi @scastiel, could you please review and merge this feature when you have a chance? This is definitely required for the app. Thanks!

[ChristopherJohnston]

@scastiel I think the app will benefit greatly from this PR

[shynst]

Might also be good to have the activity history for an individual expense at the bottom of the edit expense page.

Great idea!

[scastiel]

Thanks a lot @dcbr, amazing contribution!