Integration + Fixes

[thanasis457]

Description

For the first part of the ticket look at #298 and integrate it into the website (ie. Provider Builder and Map Provider Entries) just like with previous components.

For the second part please fix the following bugs and issues (note that most of them are independent of each other):

• The station number on the Provider Builder should never be negative. Fix this by not allowing users to enter negative numbers.
• On the home page, the waitlist textbox sometimes stays grayed out even if the email inserted is correct. From my testing this happens when you copy-paste an email into it. Please fix this and ensure the textbox gets grayed out correctly.
• Change the logout button logo to an exit sign.