add type safe ParseForm syntax

[crhntr]

{{define `ParseForm["net/url.".Values]`}}
<form method="PORT" action="/example">
  <textarea id="description"></textarea>
  <button type="submit">
</form>
{{end}}

{{define "GET / CreateExample(form)"}}
  {{- template `ParseForm["net/url.".Values]` -}}
{{end}}

note how package name is a string

The expected AST is:

• ast.IndexExpr
  • Index: ast.SelectorExpr
    • X: ast.BasicLit
    • Sel: (the type's ident)
  • X: ast.Ident
    • Name: ParseForm

[crhntr]

https://go.dev/play/p/JNHa_MJVkll