copy_and_paste: Extract functions for div creation and removal.
copy_and_paste: Extract functions for div creation and removal.

This moves div creation and removal code in the copy_handler function
to separate functions for more reusability.

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