Remove date format user setting

[chenilim]

Now that #715 will be fixed, let's use this ticket to track removing the Date format user setting.

Apologies for the round-about path this took. However, I believe the resulting design (MMMM DD, YYYY) is better overall in avoiding the need for a user setting in the first place.

[chenilim]

Hi @kamre, not sure why I can't assign this to you, but please use this ticket to submit the PR to remove the user setting. Thank you for all your help on this!

[kamre]

@chenilim @asaadmahmood Should we also change the date format for editing date in the input? Something unambiguous like YYYY-MM-DD

[asaadmahmood]

@kamre If possible, we should make it consistent to the MMMM DD, YYYY

[kamre]

@asaadmahmood I think there is no easy way to parse MMMM DD, YYYY back into Date because Intl doesn't have such functionality. And for different locales it looks really different:

Even editing this with full names of the months can lead to typos and screwing things up in my understanding.

[asaadmahmood]

@kamre Then we can just leave the format (in the input picker) as it is for now, as the user is already selecting it by himself and the input probably also gives him a visual indication of the date selected.

[kamre]

@chenilim I have created a branch for this issue based on changes for #715

So after #748 is merged I will create new pull request.