Add BuddyPress extended profile data to the export

[alex-418]

Check for Buddy Press, and if it exists, use bp_get_profile_field_data() or similar to get the extended profile data for the user (fields and values), and add this to the export array.

[alex-418]

Got a start on getting all bp profile data, to avoid having to specify a field:
$profile_data = array_map( function ( $a ) { return $a[0]; }, \BP_XProfile_ProfileData::get_all_for_user( $user->ID ) );

[alex-418]

Ended up going with: BP_XProfile_Group::get( array( 'fetch_fields' => true ) ); in https://github.com/BCcampus/excel-export/tree/buddypress