Refactor: Load UserTemplates from embedded yaml file (#575)

* Refactor: Load UserTemplates from embedded yaml file

* feat: add version field to UserTemplates

* refactor: use shell script to fetch frontends

* chore: add *-dist to .gitignore

* refactor: rename to FrontendTemplates

BREAKING CHANGE: This commit changes the `user_templates` filed
in the communication json between backend and the admin-frontend.

Keep user config.yml `user_template` filed.

script/fetch-frontends.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+set -euo pipefail
+
+ROOT_DIR="$(realpath "$(dirname "${BASH_SOURCE[0]}")/..")"
+TEMPLATES_FILE="$ROOT_DIR/service/singleton/frontend-templates.yaml"
+
+download_and_extract() {
+  local repository="$1"
+  local version="$2"
+  local targetDir="$3"
+  local TMP_DIR
+
+  TMP_DIR="$(mktemp -d)"
+
+  echo "Downloading from repository: $repository, version: $version"
+
+  pushd "$TMP_DIR" || exit
+
+  curl -L -o "dist.zip" "$repository/releases/download/$version/dist.zip"
+
+  [ -e "$targetDir" ] && rm -r "$targetDir"
+  unzip -q dist.zip
+  mv dist "$targetDir"
+
+  rm "dist.zip"
+  popd || exit
+}
+
+count=$(yq eval '. | length' "$TEMPLATES_FILE")
+
+for i in $(seq 0 $(("$count"-1))); do
+  path=$(yq -r ".[$i].path" "$TEMPLATES_FILE")
+  repository=$(yq -r ".[$i].repository" "$TEMPLATES_FILE")
+  version=$(yq -r ".[$i].version" "$TEMPLATES_FILE")
+
+  if [[ -n $path && -n $repository && -n $version ]]; then
+    download_and_extract "$repository" "$version" "$ROOT_DIR/cmd/dashboard/$path"
+  fi
+done