Create feature to log out of OECI credentials

[michaelzhang43]

Users must input OECI credentials in order to access the search tool. However, there is no feature to "log out" of these credentials, so accessing the webpage again with cookies enabled will allow the user of the same machine to log back in without inputting OECI credentials. This creates an issue when users use RecordSponge on public computers and the only way to remove OECI credentials is to clear cookies.

As such, we need a button to log out of OECI credentials.