push_notifications: Add `get_mobile_push_content()` function.
push_notifications: Add `get_mobile_push_content()` function.

Given the rendered content of a message, this function strips
all the markup replacing emojis with their corresponding unicode
representation.

eeshangarg/zulip,eeshangarg/zulip,punchagan/zulip,jackrzhang/zulip,dhcrzf/zulip,hackerkid/zulip,dhcrzf/zulip,tommyip/zulip,shubhamdhama/zulip,rht/zulip,dhcrzf/zulip,jackrzhang/zulip,timabbott/zulip,eeshangarg/zulip,kou/zulip,brockwhittaker/zulip,shubhamdhama/zulip,brainwane/zulip,timabbott/zulip,mahim97/zulip,hackerkid/zulip,shubhamdhama/zulip,tommyip/zulip,Galexrt/zulip,timabbott/zulip,andersk/zulip,mahim97/zulip,brockwhittaker/zulip,brainwane/zulip,kou/zulip,zulip/zulip,tommyip/zulip,hackerkid/zulip,synicalsyntax/zulip,hackerkid/zulip,timabbott/zulip,synicalsyntax/zulip,synicalsyntax/zulip,eeshangarg/zulip,kou/zulip,brainwane/zulip,mahim97/zulip,synicalsyntax/zulip,mahim97/zulip,showell/zulip,brainwane/zulip,eeshangarg/zulip,timabbott/zulip,brockwhittaker/zulip,showell/zulip,andersk/zulip,rishig/zulip,Galexrt/zulip,shubhamdhama/zulip,punchagan/zulip,andersk/zulip,shubhamdhama/zulip,punchagan/zulip,mahim97/zulip,punchagan/zulip,dhcrzf/zulip,rishig/zulip,rht/zulip,Galexrt/zulip,brainwane/zulip,Galexrt/zulip,kou/zulip,rishig/zulip,dhcrzf/zulip,punchagan/zulip,timabbott/zulip,zulip/zulip,synicalsyntax/zulip,jackrzhang/zulip,andersk/zulip,rht/zulip,zulip/zulip,tommyip/zulip,punchagan/zulip,tommyip/zulip,brainwane/zulip,hackerkid/zulip,dhcrzf/zulip,zulip/zulip,eeshangarg/zulip,brockwhittaker/zulip,Galexrt/zulip,rishig/zulip,kou/zulip,rht/zulip,punchagan/zulip,rht/zulip,showell/zulip,synicalsyntax/zulip,jackrzhang/zulip,andersk/zulip,shubhamdhama/zulip,kou/zulip,tommyip/zulip,mahim97/zulip,showell/zulip,rht/zulip,showell/zulip,hackerkid/zulip,brainwane/zulip,jackrzhang/zulip,brockwhittaker/zulip,zulip/zulip,dhcrzf/zulip,rishig/zulip,andersk/zulip,hackerkid/zulip,rishig/zulip,brockwhittaker/zulip,kou/zulip,synicalsyntax/zulip,eeshangarg/zulip,Galexrt/zulip,zulip/zulip,showell/zulip,rishig/zulip,jackrzhang/zulip,zulip/zulip,rht/zulip,timabbott/zulip,Galexrt/zulip,jackrzhang/zulip,shubhamdhama/zulip,showell/zulip,andersk/zulip,tommyip/zulip