Testcase widget improve containment

[pmario]

This PR fixes #8458

• 8458

  • The test-case-widget does not contain action-sendmessages
  • Or <$action- widgets in general

To Test the PR

• Use the following code with a testcase-tiddler
• title: test-new-tiddler-button
• tag: $:/tags/wiki-test-spec
• type: text/vnd.tiddlywiki-multiple

title: Narrative

This code tests action-sendmessage with tm-new-tiddler

+
title: Output

<$button>
<$action-sendmessage $message="tm-new-tiddler" />
Create a new tiddler
</$button>

This PR

• The new tiddler is created in the testcase "environment".
• It implements a very minimalistic "edit template", that only allows users to define a tiddler title.

I did Test With:

• action-createtiddler
• action-deletetiddler
• action-navigate
• action-sendmessage -- messages the are caught by the navigator-widget
• action-setfield

It seems to work well, with all messages, that the navigator-widget can handle.

@btheado, @Leilei332 -- please test this PR. See link at: https://github.com/TiddlyWiki/TiddlyWiki5/pull/8529#issuecomment-2297562500

[github-actions[bot]]

Confirmed: pmario has already signed the Contributor License Agreement (see contributing.md)

[pmario]

Test-version: https://pmario.github.io/kitchensink/8529-testcase-improve-containment.html#test-new-button

[Jermolene]

Thanks @pmario