Completion should generate only start section when empty end section is found

[angelozerr]

To support correctly surround with tag section, we need generate only start section when empty end section is found.

Given this template

{#}

completion shows for, etc, after for item apply, it generates:

{#for item in items}
  {item.name}
{/for}

Given this template which contains an empty orphan end section:

{#}
{\}

completion shows for, etc, after for item apply, it SHOULD generate:

{#for item in items}
{\}

@JessicaJHee I'm working on this issue.