node tests: Move data setup to module level for peer_data.
node tests: Move data setup to module level for peer_data.

We move some of the data setup to the top of the file.

We also remove some get_sub() calls that aren't really
necessary now that peer_data and stream_data are more
independent.

punchagan/zulip,punchagan/zulip,hackerkid/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,hackerkid/zulip,zulip/zulip,eeshangarg/zulip,zulip/zulip,zulip/zulip,kou/zulip,punchagan/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,kou/zulip,rht/zulip,rht/zulip,punchagan/zulip,zulip/zulip,hackerkid/zulip,rht/zulip,zulip/zulip,andersk/zulip,hackerkid/zulip,andersk/zulip,hackerkid/zulip,zulip/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,punchagan/zulip,andersk/zulip,andersk/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,kou/zulip,zulip/zulip,hackerkid/zulip,hackerkid/zulip,rht/zulip,eeshangarg/zulip