Fixes extended test failure and adding tags

Fixes:
   - Changing the Force tags PNOR_BIOS_Code_Update to BIOS_Code_Update
     in test_bios_update.robot
   - Added Tag Network_Nping in extended/test_network_nping.robot
   - Added Tag Network_Nping test_lists/skip_test_extended
   - Added Tag Networkd_Ext in extended/test_netwokd_ext.robot
   - Added 'REST Power On' to boot to OS in 'eSEL Test SetUp'
     in test_esel.robot

Resolves openbmc/openbmc-test-automation#726

Change-Id: Ia9b99ae94e6ac307658ff483a4c00dd2713be35a
Signed-off-by: Sweta Potthuri <spotthur@in.ibm.com>
diff --git a/test_lists/skip_test_extended b/test_lists/skip_test_extended
index 3b7f331..0228295 100644
--- a/test_lists/skip_test_extended
+++ b/test_lists/skip_test_extended
@@ -1,5 +1,5 @@
 -e Initiate_Code_Update_BMC
--e PNOR_BIOS_Code_Update
+-e BIOS_Code_Update
 -e Run_Keyword_Pgm
 -e Factory_Reset
 -e Full_Suite_Regression
@@ -7,6 +7,7 @@
 -e Host_Network
 -e Networkd_Ext
 -e NetworkManager
+-e Network_Nping
 -e Run_Multiple_Power_Cycle
 -e General_boot_testing
 -e Upload_Test