Add a `StaticVector` pretty-printer for GDB

[glebm]

Previously, printing a StaticVector in gdb printer the size and the raw bytes of data_.

Example of using this pretty-printer:

$ gdb -iex 'add-autoload-safe-path .' build/devilutionx
(gdb) b Source/engine/load_file.hpp:126
(gdb) run
(gdb) p files
$1 = devilution::StaticVector<devilution::AssetRef, 6> of length 5 = {{archive = 0x55555c8d7460 <devilution::diabdat_mpq>, fileNumber = 1420,
    filename = "monsters\\zombie\\zombien.cl2", directHandle = 0x0}, {archive = 0x55555c8d7460 <devilution::diabdat_mpq>, fileNumber = 1421,
    filename = "monsters\\zombie\\zombiew.cl2", directHandle = 0x0}, {archive = 0x55555c8d7460 <devilution::diabdat_mpq>, fileNumber = 1422,
    filename = "monsters\\zombie\\zombiea.cl2", directHandle = 0x0}, {archive = 0x55555c8d7460 <devilution::diabdat_mpq>, fileNumber = 1423,
    filename = "monsters\\zombie\\zombieh.cl2", directHandle = 0x0}, {archive = 0x55555c8d7460 <devilution::diabdat_mpq>, fileNumber = 1424,
    filename = "monsters\\zombie\\zombied.cl2", directHandle = 0x0}}

The pretty-printer implements the full array printer protocol, so it even works in IDEs.

For VS Code and CMake, add the following to your .vscode/settings.json:

"cmake.debugConfig": {
    "setupCommands": [
        {
            "description": "Enable pretty-printing for gdb",
            "text": "-enable-pretty-printing",
            "ignoreFailures": true
        },
        {
            "description": "Load StaticVector pretty-printer"
            "text": "source ${workspaceFolder}/tools/gdb/pretty_printers/utils/static_vector_pp.py",
            "ignoreFailures": false
        }
    ]
}

To get this: