[cmake, docs, tools] update CPMUtil (#3183)

Rewrote the entire tooling scheme. That's about it, just make sure
tooling works as expected everywhere.

Signed-off-by: crueter <crueter@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3183
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: Lizzie <lizzie@eden-emu.dev>

tools/cpm/package/add.sh

@@ -0,0 +1,79 @@
+#!/bin/sh -e
+
+# SPDX-FileCopyrightText: Copyright 2025 crueter
+# SPDX-License-Identifier: LGPL-3.0-or-later
+
+RETURN=0
+
+usage() {
+	cat <<EOF
+Usage: cpmutil.sh package add [-s|--sha] [-t|--tag]
+           [-c|--cpmfile CPMFILE] [package name]
+
+Add a new package to a cpmfile.
+
+Options:
+    -t, --tag            	Use tag versioning, instead of the default,
+                           	commit sha versioning.
+    -c, --cpmfile <CPMFILE>	Use the specified cpmfile instead of the root cpmfile
+
+Note that you are still responsible for integrating this into your CMake.
+
+EOF
+
+	exit $RETURN
+}
+
+die() {
+	echo "-- $*" >&2
+	exit 1
+}
+
+_cpmfile() {
+	[ -z "$1" ] && die "You must specify a valid cpmfile."
+	CPMFILE="$1"
+}
+
+while :; do
+	case "$1" in
+	-[a-z]*)
+		opt=$(printf '%s' "$1" | sed 's/^-//')
+		while [ -n "$opt" ]; do
+			# cut out first char from the optstring
+			char=$(echo "$opt" | cut -c1)
+			opt=$(echo "$opt" | cut -c2-)
+
+			case "$char" in
+			t) TAG=1 ;;
+			c)
+				_cpmfile "$2"
+				shift
+				;;
+			h) usage ;;
+			*) die "Invalid option -$char" ;;
+			esac
+		done
+		;;
+	--tag) TAG=1 ;;
+	--cpmfile)
+		_cpmfile "$2"
+		shift
+		;;
+	--help) usage ;;
+	"$0") break ;;
+	"") break ;;
+	*) PKG="$1" ;;
+	esac
+
+	shift
+done
+
+: "${CPMFILE:=$PWD/cpmfile.json}"
+
+[ -z "$PKG" ] && die "You must specify a package name."
+
+export PKG
+export CPMFILE
+export TAG
+
+"$SCRIPTS"/util/interactive.sh