images: Use GNU less instead of busybox

Busybox less does not support colors and tools
like nmcli output to less and has it does not support
colors characters escape characters are printed and the pager is
open instead of just printing out to the console

See : https://github.com/resin-os/meta-resin/pull/964

recipes-core/images/netmodule-linux-image-minimal.bb

@@ -21,6 +21,7 @@ IMAGE_INSTALL = " \
     board-descriptor \
     curl \
     tar \
+    less \
     kernel-devicetree \
     "
 

recipes-core/images/netmodule-linux-image.bb

@@ -66,6 +66,7 @@ IMAGE_INSTALL_append = " \
                 bridge-utils \
                 gpsd \
                 curl \
+                less \
                 ${FIRMWARE} \
                 "