Add the line protocol syntax reference for InfluxDB 3 Cloud

Cloud pages don't exist yet at the paths below, so [`content/influxdb3/cloud/request-information.md`](https://github.com/influxdata/docs-v2/blob/master/content/influxdb3/cloud/request-information.md) aliases them to a "Request more information" page. Publish the real content and remove the alias.

Closest existing equivalent to source from: `/influxdb3/enterprise/reference/syntax/line-protocol/`

## Aliased paths

- [ ] `/influxdb3/cloud/reference/syntax/line-protocol/`

## Done when

- [ ] Content is published (or the linking shared content is gated for Cloud)
- [ ] The alias is removed from `request-information.md`
- [ ] Any hidden anchor ``s that belonged to these paths are removed
- [ ] `link-checker` passes

Part of #7391.

Compare the existing content at /influxdb3/enterprise/reference/syntax/line-protocol/ with the Cloud documentation paths. Start with content/influxdb3/cloud/request-information.md, remove the relevant alias and any hidden anchor spans, then verify the Cloud content or shared-content gating and run link-checker. Done means the line protocol reference is published at the Cloud path and link-checker passes.

Written by the indexing model from the issue text.