This patch adds the alternate_shortcut member to LibGUI::Action, which
enables one Action to have two keyboard shortcuts.
Note that the string used in menus and tooltips only shows the main
shortcut, which is the same behaviour as in Firefox and Chrome.
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 *
Actions can now have a longer text description, in addition to its
regular UI string. The longer text will soon be used to display
a more detailed description of hovered actions in statusbars.
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
