feat(browser): Experimental Soft Navigation Support

[logaretm]

This PR implements soft navigation support which is pulled from GoogleChrome/web-vitals#308 which entered recently origin trials.

No plans yet to support this in our product, just experimenting with how it works once I submit a suitable origin to test out.

Links:

• https://developer.chrome.com/docs/web-platform/soft-navigations-experiment
• https://developer.chrome.com/blog/new-soft-navigations-origin-trial

[linear]

JS-1019 Investigate and Experiment with soft navigation web vitals

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	24.59 kB	added	added
@sentry/browser - with treeshaking flags	23.09 kB	added	added
⛔️ @sentry/browser (incl. Tracing) (max: 41.3 kB)	42.13 kB	added	added
@sentry/browser (incl. Tracing, Profiling)	46.46 kB	added	added
⛔️ @sentry/browser (incl. Tracing, Replay) (max: 80 kB)	80.58 kB	added	added
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	70.25 kB	added	added
⛔️ @sentry/browser (incl. Tracing, Replay with Canvas) (max: 85 kB)	85.25 kB	added	added
⛔️ @sentry/browser (incl. Tracing, Replay, Feedback) (max: 97 kB)	97.47 kB	added	added
@sentry/browser (incl. Feedback)	41.27 kB	added	added
@sentry/browser (incl. sendFeedback)	29.26 kB	added	added
@sentry/browser (incl. FeedbackAsync)	34.19 kB	added	added
@sentry/react	26.28 kB	added	added
⛔️ @sentry/react (incl. Tracing) (max: 43.3 kB)	44.15 kB	added	added
@sentry/vue	29.07 kB	added	added
⛔️ @sentry/vue (incl. Tracing) (max: 43.1 kB)	43.94 kB	added	added
@sentry/svelte	24.6 kB	added	added
CDN Bundle	26.89 kB	added	added
⛔️ CDN Bundle (incl. Tracing) (max: 42 kB)	42.75 kB	added	added
CDN Bundle (incl. Tracing, Replay)	79.24 kB	added	added
CDN Bundle (incl. Tracing, Replay, Feedback)	84.75 kB	added	added
CDN Bundle - uncompressed	78.84 kB	added	added
⛔️ CDN Bundle (incl. Tracing) - uncompressed (max: 125 kB)	127.15 kB	added	added
CDN Bundle (incl. Tracing, Replay) - uncompressed	243.19 kB	added	added
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	255.95 kB	added	added
⛔️ @sentry/nextjs (client) (max: 46 kB)	46.25 kB	added	added
⛔️ @sentry/sveltekit (client) (max: 42 kB)	42.55 kB	added	added
@sentry/node-core	50.76 kB	added	added
@sentry/node	157.84 kB	added	added
@sentry/node - without tracing	92.64 kB	added	added
@sentry/aws-serverless	106.4 kB	added	added