Changing XAML editor to use Monaco editor

[nickrandolph]

GitHub Issue (If applicable): #139

PR Type

What kind of change does this PR introduce?

• Feature

What is the current behavior?

XAML editor is simple textbox

What is the new behavior?

XAML editor uses the Monaco editor which can provide intellisense and code highlighting

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Docs have been added/updated which fit documentation template. (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Wasm UI Tests are not showing unexpected any differences. Validate PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Updated the Release Notes
• Associated with an issue (GitHub or internal)

Other information

Internal Issue (If applicable):

[CLAassistant]

All committers have signed the CLA.

[nickrandolph]

@carldebilly let me know what you think. I think before this PR is merged, it would be good to work out how the monaco editor files could be included in the MonacoEditorComponet, rather than explicitly added as source code.

[nickrandolph]

@carldebilly I've fixed up the Uno.Monaco.Editor nuget package so we don't need to include all the monaco source files here (or anywhere else that wants to use the Monaco Editor)

[nickrandolph]

@carldebilly / @jeromelaban I've update the playground to include basic intellisense and error highlighting (see attached gif)

[MelbourneDeveloper]

@nickrandolph amazing!

[jeromelaban]

@nickrandolph loving this !!Very nice work :)

[CyborgDE]

Is not working in the current version :-(
https://playground.platform.uno/

I figured out, I have to desantize the result :
var registerCompletionItemProvider = (languageId, characters) =>
monaco.languages.registerCompletionItemProvider(languageId,
{
triggerCharacters: characters,
provideCompletionItems: (model, position, context, token) => callParentEventAsync(
"CompletionItemProvider" + languageId,
[JSON.stringify(position), JSON.stringify(context)]).then(result => {
if (result) {
return JSON.parse(desantize(result));
}
return null;
}),
resolveCompletionItem: (item, token) => callParentEventAsync("CompletionItemRequested" + languageId,
[JSON.stringify(item)]).then(result => {
if (result) {
return JSON.parse(desantize(result));
}
return null;
})
});