feat: support proxying

[noahjohnhay]

No description provided.

[adoroszlai]

Using closer.lua would help direct traffic to CDN for releases available there (example). For older releases, it redirects to archive (example).

Suggested change

	local base="${ASDF_MAVEN_MIRROR:=https://archive.apache.org/dist/maven}"
	local url="$base/maven-$major/$version/binaries/apache-maven-$version-bin.tar.gz"
	local path="maven-$major/$version/binaries/apache-maven-$version-bin.tar.gz"
	local url="https://www.apache.org/dyn/closer.lua/maven/$path?action=download"
	if [[ -n "${ASDF_MAVEN_MIRROR:-}" ]]; then
	url="${ASDF_MAVEN_MIRROR}/$path"
	fi