list_render: Convert sorting_functions from object to Map.
list_render: Convert sorting_functions from object to Map.

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

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