fix(replay): Ensure we still truncate large bodies if they are failed JSON

[mydea]

This also incorporates feedback from @Lms24 to properly handle the case when we both fail to parse JSON AND still truncate the body.

[mydea]

cc @ryan953 so you are aware which combinations of warnings are possible:

• nothing
• JSON_TRUNCATED
• TEXT_TRUNCATED
• INVALID_JSON
• INVALID_JSON & TEXT_TRUNCATED

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	21.03 KB (+0.05% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	65.66 KB (+0.03% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.56 KB (+0.04% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	58.12 KB (+0.03% 🔺)
@sentry/browser - Webpack (gzipped + minified)	21.17 KB (+0.03% 🔺)
@sentry/browser - Webpack (minified)	69.07 KB (+0.03% 🔺)
@sentry/react - Webpack (gzipped + minified)	21.19 KB (+0.03% 🔺)
@sentry/nextjs Client - Webpack (gzipped + minified)	49.03 KB (+0.01% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	28.59 KB (+0.02% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	26.82 KB (+0.03% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	46.05 KB (+0.02% 🔺)
@sentry/replay - Webpack (gzipped + minified)	39.93 KB (+0.03% 🔺)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	64.92 KB (+0.02% 🔺)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	57.9 KB (+0.03% 🔺)