TASK Refactor ContentContext methods

[dlubitz]

This rector replaces removed ContentContext calls in PHP and Fusion. For better detection of context objects all Node(Interface)s get replaced by Neos\Rector\ContentRepository90\Legacy\NodeLegacyStub. The Neos\Rector\ContentRepository90\Legacy\NodeLegacyStub get replaced at the end by Neos\ContentRepository\Core\Projection\ContentGraph\Node

PHP

• ContentContext::isInBackend => $this->renderingModeService->findByCurrentUser()->isEdit
• ContentContext::isLive => !$this->renderingModeService->findByCurrentUser()->isEdit && !$this->renderingModeService->findByCurrentUser()->isPreview
• ContentContext::getCurrentRenderingMode => $this->renderingModeService->findByCurrentUser()
• ContentContext::getCurrentSiteNode => Warning, no replacement
• ContentContext::getCurrentDomain => Warning, no replacement
• ContentContext::getCurrentSite => Warning, no replacement

Fusion

• node.context.currentDomain => Warning, no replacement
• context.currentSiteNode => Warning, no replacement

Fixes #31