Add standard emojis on desktop

The emoji dialog on the compose pane on Phanpy only features the custom emojis from the current instance, not the "standard" ones.
When using Phanpy on desktop, the emojis provided by the Android keyboard aren't available, so I have to cut/paste them from another source, that's uncomfortable.
Please, include a standard set of emojis besides the custom ones.
Many thanks

Start by locating the compose pane's emoji dialog and the code that loads custom emojis from the current Mastodon instance. Add a standard emoji set alongside the custom emojis for desktop use, then verify that both sets are available in the picker.

Written by the indexing model from the issue text.