streams: Refactor `setup_subscriptions_stream_hash` arguments.
streams: Refactor `setup_subscriptions_stream_hash` arguments.

This refactors the arguments in the `setup_subscriptions_stream_hash`
method to remove the `stream_id` param and just take it from the `sub`
argument it is passed (which is an object that contains the property,
`stream_id`.

showell/zulip,timabbott/zulip,eeshangarg/zulip,Galexrt/zulip,timabbott/zulip,synicalsyntax/zulip,jackrzhang/zulip,hackerkid/zulip,brockwhittaker/zulip,hackerkid/zulip,rht/zulip,hackerkid/zulip,rishig/zulip,hackerkid/zulip,timabbott/zulip,kou/zulip,mahim97/zulip,andersk/zulip,andersk/zulip,dhcrzf/zulip,timabbott/zulip,shubhamdhama/zulip,jackrzhang/zulip,rht/zulip,punchagan/zulip,zulip/zulip,kou/zulip,shubhamdhama/zulip,andersk/zulip,showell/zulip,eeshangarg/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,Galexrt/zulip,synicalsyntax/zulip,rishig/zulip,hackerkid/zulip,eeshangarg/zulip,showell/zulip,andersk/zulip,brockwhittaker/zulip,mahim97/zulip,synicalsyntax/zulip,zulip/zulip,brainwane/zulip,punchagan/zulip,hackerkid/zulip,rishig/zulip,jackrzhang/zulip,tommyip/zulip,brockwhittaker/zulip,dhcrzf/zulip,rht/zulip,rht/zulip,brainwane/zulip,punchagan/zulip,showell/zulip,tommyip/zulip,rishig/zulip,Galexrt/zulip,hackerkid/zulip,synicalsyntax/zulip,jackrzhang/zulip,tommyip/zulip,mahim97/zulip,brainwane/zulip,rishig/zulip,timabbott/zulip,eeshangarg/zulip,shubhamdhama/zulip,synicalsyntax/zulip,shubhamdhama/zulip,eeshangarg/zulip,synicalsyntax/zulip,brainwane/zulip,kou/zulip,shubhamdhama/zulip,rishig/zulip,jackrzhang/zulip,tommyip/zulip,shubhamdhama/zulip,shubhamdhama/zulip,rht/zulip,mahim97/zulip,punchagan/zulip,mahim97/zulip,tommyip/zulip,brockwhittaker/zulip,kou/zulip,tommyip/zulip,brainwane/zulip,eeshangarg/zulip,punchagan/zulip,brainwane/zulip,andersk/zulip,zulip/zulip,Galexrt/zulip,brockwhittaker/zulip,punchagan/zulip,brainwane/zulip,showell/zulip,Galexrt/zulip,zulip/zulip,kou/zulip,rishig/zulip,rht/zulip,zulip/zulip,tommyip/zulip,dhcrzf/zulip,Galexrt/zulip,brockwhittaker/zulip,andersk/zulip,dhcrzf/zulip,kou/zulip,synicalsyntax/zulip,zulip/zulip,timabbott/zulip,timabbott/zulip,dhcrzf/zulip,dhcrzf/zulip,jackrzhang/zulip,punchagan/zulip,jackrzhang/zulip,showell/zulip,dhcrzf/zulip,Galexrt/zulip,showell/zulip,andersk/zulip,zulip/zulip,mahim97/zulip