To prevent lag when the displayed code points are redrawn in support of
a search box, only create the GUI::Button objects for the emoji a single
time. Re-use those buttons when adding them to the dialog.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
