Add field for custom wiki username in database

webclient/src/Account.js

@@ -250,8 +250,13 @@ export function AccountForm(props) {
 				{...makeProps('emergency_contact_phone')}
 			/>
 
+			{member.mediawiki_username && <div className='field'>
+				<label>Custom Wiki Username</label>
+				<p>{member.mediawiki_username}</p>
+			</div>}
+
 			{member.discourse_username && <Form.Input
-				label='Forum Username'
+				label='Custom Forum Username'
 				autoComplete='off'
 				{...makeProps('discourse_username')}
 			/>}

webclient/src/Auth.js

@@ -110,7 +110,7 @@ export function AuthWiki(props) {
 				<Header size='small'>Success!</Header>
 				<p>You can now log into the Wiki:</p>
 				{user && <p>
-					Username: {user.username}<br/>
+					Username: {user.member.mediawiki_username || user.username}<br/>
 					Password: [this Spaceport password]
 				</p>}
 				<p><a href='https://wiki.protospace.ca/index.php?title=Special:UserLogin&returnto=Welcome+to+Protospace' rel='noopener noreferrer'>Protospace Wiki</a></p>