Medium: UI fixes in Dialog Settings view

[hagitmer]

• Text field to name this group isn't really a text field. It should be a text field that the user can type in directly, and saves when the user exits the settings. Currently, tapping the text field gives the user a modal with a text field in it. The grey suggestion text should just be "Name this group" instead of the name of the group. Remove the pencil icon on the right. Zeplink: https://zpl.io/ZEtwFB

• Fix line weight in "Leave Message" cell / footer. The line style needs to be 0.5px, #A6B4BF. Ref Image:https://www.dropbox.com/s/3g8ysmvl6i9ruqp/WH-14.png?dl=0

• Copy Change: 'Members' (2nd list item) should say 'Group Members'

• Copy Change: 'Mute Conversation' (3rd list item) should say 'Mute Push Notifications'

• Copy Change: 'Leave Conversation' (red outline button) should say 'Leave Message'