[BEAM-13475] [Playground] [Bugfix] Error message disappears too quick

[miamihotline]

Changed showSnackbar to showAlignedDialog, added SelectableText inside error notifications, added RunCode errors to output.

New dependency: https://pub.dev/packages/aligned_dialog

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ValidatesRunner compliance status (on master branch)

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Examples testing status on various runners

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Post-Commit SDK/Transform Integration Tests Status (on master branch)

Go	Java	Python

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website	Whitespace	Typescript
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