recent_topics: Hide participants and last msg time on <750px width.
recent_topics: Hide participants and last msg time on <750px width.

This ensures the UI experience on <750px width doesn't look
like too many things packed in a small space.

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