ViewTeam, SeeInvites state refactors and updates to MenuOverlay Navigator push logic

[rlyss]

Changes

Team state refactors

• Added a UserInfoProvider which stores global state on the user Profile, Team and api access token
• Refactored CreateTeam, SeeInvites and ViewTeam pages to use the UserInfoProvider state instead of making API calls each time
• Those pages now automatically update based on changes to the UserInfoProvider state without having to push a new page to display the updated information
• Replaced functional widgets with classes for SeeInvites and ViewTeam pages

SeeInvites page

• Added pull down to refresh list of invites

MenuOverlay

• Updated navigation such that there is only at most one page above the Home page at any time rather than stacking each new page on top of all previous pages
• "Team" button now correctly navigates to ViewTeam or TeamsList (no longer needs double segue, solves #58)
• Minor fix to theming (yellow text underlines are now gone)

CreateTeam

• Removed "INVITE NEW MEMBER" button (functionality duplicated in ViewTeam screen)

TeamsList page

• Updated "Pending response" text color

[jhong66]

Teams Page Color Tweaks:

• Adjusted colors of cards on Teams List page to match styling of invite cards
• Changed color of mail (view invites) and star (marks team admin) icons to yellow to match card color change