debian: split osmo-remsim-client into osmo-remsim-client-{shell,st2}

The -shell client has no dependency to libosmo-simtrace2, so it makes
sense to package it separately.

Change-Id: I6c634572af5036fd7f9ce1fee6d1474e06bdaa5a
diff --git a/debian/osmo-remsim-client-shell.install b/debian/osmo-remsim-client-shell.install
new file mode 100644
index 0000000..3216187
--- /dev/null
+++ b/debian/osmo-remsim-client-shell.install
@@ -0,0 +1 @@
+usr/bin/osmo-remsim-client-shell