Support for new sysrepo flags

[rbu9fe]

There are 3 new sysrepo sr_subscr_flag_t values:

• SR_SUBSCR_OPER_POLL_DIFF = 0x80
• SR_SUBSCR_FILTER_ORIG = 0x0100
• SR_SUBSCR_CHANGE_ALL_MODULES = 0x0200

Could you please add them to the SubscribeOptions?

I didn't check other enums, perhaps there are more changes...