Add <$testcase> widget (#7817)

* Initial Commit

* Add note to preview build

* Fix whitespace and indenting

Thanks @pmario

* Fix crash with unset $tiddler attribute on <$data> widget

Thanks @CodaCodr

* Don't duplicate "description" field in test cases

* Use different background colours for nested testcase widgets

* Extend the testcase widget to run tests

* Add testcases to control panel

* Add a view template body template to render testcase tiddlers

* Test edition should display testcases

* Whitespace fixes

* Make testcase tiddler tempalte link to itself

* Styling tweaks

* Docs improvements

* Styling tweaks

* Run the new tw5.com testcases in the test edition

* Update data widget to display its content in JSON

* Add testcase convenience procedure

* Clearer testcases for data widget, and docs tweaks

* Don't expect our intentionally failing test to pass

* Extend testcase default template so that the display format can be chosen

It is selected by setting the variable "displayFormat"

* DataWidget docs typo

* Fix data widget not refreshing

* Links in testcase output switch to the tab containing that tiddler

Thanks to @btheado for the suggestion

* Docs update for 648855e8a5

* Wording tweak

* Add support for narrative tiddlers in test cases

* Documentation improvements

* Cleanup comments

* Remove obsolete code comments

* Simplify template

* Docs update

* Rename $:/core/ui/testcases/DefaultTemplate/SourceTabs from $:/core/ui/testcases/DefaultTemplate/Source

* Use the view template body for failing tests

* Don't reference the geospatial plugin

* "Test case" should be two words

* Fix handling of currentTiddler variable

Fixes problem reported by @btheado in https://github.com/Jermolene/TiddlyWiki5/pull/7817#issuecomment-2103704468

* Prepare for merging

core/ui/ControlPanel/TestCases.tid

@@ -0,0 +1,10 @@
+title: $:/core/ui/ControlPanel/TestCases
+tags: $:/tags/ControlPanel/Advanced
+caption: {{$:/language/ControlPanel/TestCases/Caption}}
+
+\whitespace trim
+{{$:/language/ControlPanel/TestCases/Hint}}
+
+<div class="tc-control-panel">
+<$macrocall $name="tabs" tabsList="[all[shadows+tiddlers]tag[$:/tags/ControlPanel/TestCases]!has[draft.of]]" default="$:/core/ui/ControlPanel/TestCases/All"/>
+</div>

core/ui/ControlPanel/TestCasesAll.tid

@@ -0,0 +1,24 @@
+title: $:/core/ui/ControlPanel/TestCases/All
+tags: $:/tags/ControlPanel/TestCases
+caption: {{$:/language/ControlPanel/TestCases/All/Caption}}
+
+\define lingo-base() $:/language/ControlPanel/
+<<lingo TestCases/All/Hint>>
+
+<$list filter="[all[tiddlers+shadows]tag[$:/tags/wiki-test-spec]type[text/vnd.tiddlywiki-multiple]] [all[tiddlers+shadows]tag[$:/tags/wiki-test-spec-failing]type[text/vnd.tiddlywiki-multiple]]">
+
+<h2>
+
+<$link>
+
+<$text text=<<currentTiddler>>/>
+
+</$link>
+
+</h2>
+
+<$transclude
+	$tiddler="$:/core/ui/TestCaseTemplate"
+/>
+
+</$list>

core/ui/ControlPanel/TestCasesFailed.tid

@@ -0,0 +1,15 @@
+title: $:/core/ui/ControlPanel/TestCases/Failed
+tags: $:/tags/ControlPanel/TestCases
+caption: {{$:/language/ControlPanel/TestCases/Failed/Caption}}
+
+\define lingo-base() $:/language/ControlPanel/
+<<lingo TestCases/Failed/Hint>>
+
+<$list filter="[all[tiddlers+shadows]tag[$:/tags/wiki-test-spec]type[text/vnd.tiddlywiki-multiple]] [all[tiddlers+shadows]tag[$:/tags/wiki-test-spec-failing]type[text/vnd.tiddlywiki-multiple]]">
+
+<$transclude
+	$tiddler="$:/core/ui/TestCaseTemplate"
+	hideIfPass="yes"
+/>
+
+</$list>