context: add support for rlimit.<resource> = <value>

Add support for rlimit.<resource> = <value> in the context.properties to
adjust the rlimits of the process. A value of -1 sets the max limit.

This can be used to increase the number of file descriptors in a
pipewire process when select() is not used, for example. Other resource
limits might be interesting as well maybe.

Fixes #4047

src/daemon/pipewire-pulse.conf.in

@@ -14,6 +14,7 @@ context.properties = {
     #mem.allow-mlock = true
     #mem.mlock-all   = false
     #log.level       = 2
+    #rlimit.nofile   = -1
 
     #default.clock.quantum-limit = 8192
 }

src/daemon/pipewire.conf.in

@@ -21,6 +21,7 @@ context.properties = {
     #clock.power-of-two-quantum            = true
     #log.level                             = 2
     #cpu.zero.denormals                    = false
+    #rlimit.nofile                         = -1
 
     #loop.rt-prio = -1            # -1 = use module-rt prio, 0 disable rt
     #loop.class = data.rt