pidgin/pidgin

Move PurpleAccountPresence and PurpleBuddyPresence to their own files

split purpleaccountpresence and purplebuddypresence out to their own files. Going to clean up the `update_idle` methods and convert them from `time_t` to `GDateTime` in another PR, so I didn't do anything aside from the bare minimum in them right now.

Testing Done:
ran and verified logins still work.

Reviewed at https://reviews.imfreedom.org/r/122/
---
id: im.pidgin.Finch3
runtime: org.gnome.Platform
runtime-version: '3.36'
sdk: org.gnome.Sdk
command: finch3
finish-args:
- --share=ipc
- --socket=x11
- --share=network
- --talk-name=org.freedesktop.Notifications
- --system-talk-name=org.freedesktop.Avahi
modules:
- packaging/flatpak/libpurple-common.yml
- packaging/flatpak/libgnt.yml
- name: finch3
buildsystem: meson
config-opts:
- -Dgtkui=false
- -Ddoc=false
sources:
- type: dir
path: '.'