tests: Remove obsolete page_params test setup.
tests: Remove obsolete page_params test setup.

This test code has basically been dead since
we started passing in `params` to
`stream_data.initialize()`, and now it's
more confusing than helpful.

zulip/zulip,synicalsyntax/zulip,synicalsyntax/zulip,hackerkid/zulip,eeshangarg/zulip,hackerkid/zulip,zulip/zulip,andersk/zulip,zulip/zulip,synicalsyntax/zulip,eeshangarg/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,timabbott/zulip,timabbott/zulip,andersk/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,eeshangarg/zulip,rht/zulip,shubhamdhama/zulip,shubhamdhama/zulip,rht/zulip,andersk/zulip,brainwane/zulip,punchagan/zulip,punchagan/zulip,shubhamdhama/zulip,shubhamdhama/zulip,eeshangarg/zulip,brainwane/zulip,rht/zulip,punchagan/zulip,kou/zulip,punchagan/zulip,showell/zulip,rht/zulip,shubhamdhama/zulip,zulip/zulip,showell/zulip,brainwane/zulip,zulip/zulip,synicalsyntax/zulip,synicalsyntax/zulip,synicalsyntax/zulip,hackerkid/zulip,hackerkid/zulip,showell/zulip,rht/zulip,synicalsyntax/zulip,timabbott/zulip,hackerkid/zulip,andersk/zulip,timabbott/zulip,kou/zulip,brainwane/zulip,punchagan/zulip,zulip/zulip,andersk/zulip,timabbott/zulip,hackerkid/zulip,showell/zulip,timabbott/zulip,rht/zulip,punchagan/zulip,punchagan/zulip,kou/zulip,rht/zulip,brainwane/zulip,brainwane/zulip,andersk/zulip,timabbott/zulip,shubhamdhama/zulip,brainwane/zulip,kou/zulip,kou/zulip,showell/zulip,showell/zulip,hackerkid/zulip,shubhamdhama/zulip,showell/zulip,eeshangarg/zulip