feat: custom template engine

[lars-berger]

• Replace liquidjs with custom templating engine.

New syntax:

@for (workspace in glazewm.workspaces) {
  @if (workspace.state == 'focused') {
    <button class="focused-workspace">
      {{ workspace.name }}
    </button>
  } @else if (workspace.state == 'active') {
    <button class="active-workspace" onclick="{{ focus_workspace }}">
      {{ workspace.name }}
    </button>
  } @else {
    <button class="normal-workspace" onclick="{{ focus_workspace }}">
      {{ workspace.name }}
    </button>
  }
}

Old syntax (liquidjs):

{% for workspace in glazewm.workspaces %}
  {% if workspace.state == 'focused' %}
    <button class="focused-workspace">
      {{ workspace.name }}
    </button>
  {% elsif workspace.state == 'active' %}
    <button class="active-workspace" onclick="{{ focus_workspace }}">
      {{ workspace.name }}
    </button>
  {% else %}
    <button class="normal-workspace" onclick="{{ focus_workspace }}">
      {{ workspace.name }}
    </button>
  {% endif %}
{% endfor %}