fix(surveys): Render feedback preview

[liyiy]

Changes

1. Adds support for feedback widget previews
2. Fixes a major issue when loading survey preview methods for feat(surveys): replace surveys preview posthog#20321 where generateSurveys from the modules file was overriding the generateSurveys that we want from the iife file, causing callSurveys to not show surveys normally. So we have to either split them up into separate loader files or find a way to distinguish moment in time which script is calling loader-surveys 🤔

Checklist

• Tests for new code (see advice on the tests we use)
• Accounted for the impact of any changes across different browsers
• Accounted for backwards compatibility of any changes (no breaking changes in posthog-js!)

[github-actions]

Size Change: -70.3 kB (-8%) ✅

Total Size: 854 kB

Filename	Size	Change
dist/surveys.esm.js	0 B	-64.2 kB (removed)	🏆
dist/surveys.js	58.3 kB	-6.03 kB (-9%)	✅

ℹ️ View Unchanged

Filename	Size
dist/array.full.js	183 kB
dist/array.js	125 kB
dist/es.js	125 kB
dist/exception-autocapture.js	12 kB
dist/module.js	125 kB
dist/recorder-v2.js	106 kB
dist/recorder.js	58.6 kB
dist/surveys-module-previews.js	62 kB

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