integrations: Convert CATEGORIES from object to Map.
integrations: Convert CATEGORIES from object to Map.

Signed-off-by: Anders Kaseorg <dfdb7392591db597bc41cf266a9c3bc12a2706e5@zulipchat.com>

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