Support account on tmpfs via net/ scripts (bp #14459) (#14620)

* multinode-demo: Pass --accounts through bootstrap leader wrapper

(cherry picked from commit 327be55acc)

* gce.sh: Factor out default custom memory

(cherry picked from commit ddf1d2dbf5)

* net/: Support accounts on swap-backed tmpfs

(cherry picked from commit ff599ace4d)

* net/gce.sh: Add cusom RAM arg instead of doubling default with tmpfs

(cherry picked from commit 3175cf1deb)

Co-authored-by: Trent Nelson <trent@solana.com>

net/scripts/ec2-provider.sh

@@ -7,6 +7,10 @@ cloud_DefaultZone() {
   echo "us-east-1b"
 }
 
+cloud_DefaultCustomMemoryGB() {
+  : # Not implemented
+}
+
 cloud_RestartPreemptedInstances() {
   : # Not implemented
 }