op-mode: T6694: Move some op-mode commands in the "execute" family

'force netns' — move to 'execute shell netns'.
'force vrf'— move to 'execute shell vrf'.
'force owping' — move to 'execute owping'.
'force twping' — move to 'execute twping'.
'monitor bandwidth-test' — move to 'execute bandwidth-test`.
'telnet' — move to 'execute telnet'