Enable using wget if curl is not installed

[Chemaclass]

Status quo

Currently, curl is expected to be installed to be able to download an external script.

Expected

Consider checking if curl is not install, so we can use wget as fallback.

Example

Example used on bashunit:

# dependencies.sh : https://github.com/TypedDevs/bashunit/blob/main/src/dependencies.sh
function dependencies::has_curl() {
  command -v curl >/dev/null 2>&1
}

function dependencies::has_wget() {
  command -v wget >/dev/null 2>&1
}

# io.sh : https://github.com/TypedDevs/bashunit/blob/main/src/io.sh
function io::download_to() {
  local url="$1"
  local output="$2"
  if dependencies::has_curl; then
    curl -L -J -o "$output" "$url" 2>/dev/null
  elif dependencies::has_wget; then
    wget -q -O "$output" "$url" 2>/dev/null
  else
    return 1
  fi
}