Base: Remove unnecessary UID separation of multi-process Browser

After looking closely at this, I realized that we've been running
all the service processes under separate user accounts even though
there's actually no need to.

Since we already use pledge() and unveil() to limit the scope and
access of these programs, separating them to another UID doesn't
achieve anything meaningful. So let's bring them back to the "anon"
user account and simplify things.

Programs affected:

- ImageDecoder
- RequestServer
- WebContent
- WebSocket

Longer term, I'd like for all of these to get spawned for the current
desktop user somehow, possibly by some kind of session manager, or
perhaps by the Browser program itself. But for now they remain under
SystemServer's control.

Base/etc/SystemServer.ini

@@ -3,7 +3,7 @@ Socket=/tmp/portal/request
 SocketPermissions=660
 Lazy=1
 Priority=low
-User=request
+User=anon
 BootModes=text,graphical,self-test
 MultiInstance=1
 AcceptSocketConnections=1
@@ -12,7 +12,7 @@ AcceptSocketConnections=1
 Socket=/tmp/portal/webcontent
 SocketPermissions=660
 Lazy=1
-User=webcontent
+User=anon
 BootModes=graphical
 MultiInstance=1
 AcceptSocketConnections=1
@@ -21,7 +21,7 @@ AcceptSocketConnections=1
 Socket=/tmp/portal/image
 SocketPermissions=660
 Lazy=1
-User=image
+User=anon
 BootModes=graphical
 MultiInstance=1
 AcceptSocketConnections=1
@@ -37,7 +37,7 @@ Socket=/tmp/portal/websocket
 SocketPermissions=660
 Lazy=1
 Priority=low
-User=websocket
+User=anon
 BootModes=text,graphical,self-test
 MultiInstance=1
 AcceptSocketConnections=1

Base/etc/group

@@ -4,13 +4,9 @@ tty:x:2:
 phys:x:3:window,anon
 audio:x:4:anon
 utmp:x:5:
-lookup:x:10:request,websocket,anon
+lookup:x:10:anon
-request:x:11:webcontent,anon
 notify:x:12:anon
 window:x:13:anon,notify
 clipboard:x:14:anon,notify
-webcontent:x:15:anon
-image:x:16:anon,webcontent
 symbol:x:17:anon
-websocket:x:18:webcontent,anon
 users:x:100:anon

Base/etc/passwd

@@ -1,13 +1,9 @@
 root::0:0:root:/root:/bin/sh
 lookup:!:10:10:LookupServer,,,:/:/bin/false
-request:!:11:11:RequestServer,,,:/:/bin/false
 notify:!:12:12:NotificationServer,,,:/:/bin/false
 window:!:13:13:WindowServer,,,:/:/bin/false
 clipboard:!:14:14:Clipboard,,,:/:/bin/false
-webcontent:!:15:15:WebContent,,,:/:/bin/false
-image:!:16:16:ImageDecoder,,,:/:/bin/false
 symbol:!:17:17:SymbolServer,,,:/:/bin/false
-websocket:!:18:18:WebSocket,,,:/:/bin/false
 sshd:!:19:19:OpenSSH privsep,,,:/:/bin/false
 anon:!:100:100:Anonymous,,,:/home/anon:/bin/sh
 nona:!:200:200:Nona,,,:/home/nona:/bin/sh