Admin accessibility

[Nayer-Sobhy]

Can we please make sure that the admin can apply for vacation to users
so for example I (as admin) can apply for previous vacations to other users
if we can add a drop down menu at the beginning (yourself, then the rest of the people in the office)

[maayarosama]

In requesting vacation, in case the user logged in is an Admin

• Radio buttons were added to choose if the user will be requesting vacation for himself or another user
• In case another user, a select field was added to list all the users in the same office as the admin
• Vacation balance in leave reason will be adjusted to the user selected
  

[maayarosama]

Pr #367 drafted until #368 is merged

[Mahmoud-Emad]

Implemented in #367 (review)