Add test test_cli_help_spelling

Signed-off-by: Adam Seyda <adam.seyda@intel.com>
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

test/functional/resources/cas_ex.en.pws

@@ -0,0 +1,60 @@
+personal_ws-1.1 en 1
+ALRU
+CAS
+CSV
+CentOS
+DSS
+HDD
+KiB
+LANG
+LBA
+MiB
+NHIT
+NUM
+NVMe
+OCF
+RHEL
+SLES
+SSD
+SSDP
+SUSE
+TERM
+TTY
+UTF
+Ubuntu
+acp
+alru
+async
+blk
+cas
+casadm
+casctl
+conf
+config
+csv
+dev
+failover
+init
+io
+kibibytes
+lru
+metadata
+namespace
+namespaces
+nhit
+nop
+nvme
+opencas
+param
+req
+reseller
+resizing
+runtime
+sdb
+sdx
+utf
+wa
+wb
+wt
+wo
+wwn