basic: rename cap-list.c -> capability-list.c

This also renames relevant files in the same way.

Addresses https://github.com/systemd/systemd/pull/37904#discussion_r2191950396

src/basic/generate-capability-list.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eu
+set -o pipefail
+
+CC=${1:?}
+shift
+
+$CC -dM -include linux/capability.h "$@" - </dev/null | \
+       awk '/^#define[ \t]+CAP_[A-Z_]+[ \t]+/ { print $2; }' | \
+       grep -v CAP_LAST_CAP