fix(replay): Improve handling of maskAllText selector

[mydea]

This PR improves the handling of the replay maskAllText option in two ways:

1. Currently, when maskAllText === true we overwrite the maskTextSelector. However, since we set maskAllText = true by default, this means that if you configure replay like this:

new Replay({
  maskTextSelector: '[custom]'
})

This will actually be overwritten by the maskAllText selector, because internally maskAllText is true.

This PR changes this behavior so that we only overwrite it if either we explicitly state maskAllText: true, or if we do not set it at all and no maskTextSelector is specified.

So the new behavior is:

// Result: all text selector
new Replay({})

// Result: [custom]
new Replay({ maskTextSelector: '[custom]' })

// Result: all text selector
new Replay({ maskTextSelector: '[custom]', maskAllText: true })

2. Apparently, some browsers have issues with the current all text selector. I suspect the problem is the selector list in :not(), see: https://developer.mozilla.org/en-US/docs/Web/CSS/:not#browser_compatibility
   So I changed this to avoid using this selector type.

Closes #6618

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.79 KB (+0.02% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	61.3 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.57 KB (-0.01% 🔽)
@sentry/browser - ES6 CDN Bundle (minified)	54.84 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	20.34 KB (0%)
@sentry/browser - Webpack (minified)	66.48 KB (0%)
@sentry/react - Webpack (gzipped + minified)	20.36 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	47.56 KB (0%)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.75 KB (0%)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	25.19 KB (+0.02% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	42.11 KB (+0.04% 🔺)
@sentry/replay - Webpack (gzipped + minified)	38.19 KB (+0.05% 🔺)

[Lms24]

Good catch!