Add registration support to python remote API

[jleibs]

What

• Builds on top of: Plumb through initial grpc support for the python SDK #7994 to add support for a register API

Example:

import rerun as rr
import pyarrow as pa

rr.init("rerun_example_reds")
rr.save("/tmp/test.rrd")
rr.log("test", rr.TextLog("Hello, world!"))

conn = rr.remote.connect("http://0.0.0.0:51234")

resp = conn.register(
    "file:///tmp/test.rrd",
    {
        "my_col": pa.array(["c"]),
    },
)
print(f"Registered recording with id: {resp}")

Verified in the catalog:

┌─────────────────────────────────┬─────────────┬──────────────────────┬────────────────┬────────┐
│ id                              ┆ description ┆ storage_url          ┆ recording_type ┆ my_col │
│ ---                             ┆ ---         ┆ ---                  ┆ ---            ┆ ---    │
│ str                             ┆ str         ┆ str                  ┆ cat            ┆ str    │
╞═════════════════════════════════╪═════════════╪══════════════════════╪════════════════╪════════╡
│ a82d7976-f9a5-49e2-825e-ab2771… ┆             ┆ file:///tmp/test.rrd ┆ rrd            ┆ c      │
└─────────────────────────────────┴─────────────┴──────────────────────┴────────────────┴────────┘

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)
• I have tested the web demo (if applicable):
  • Using examples from latest main build: rerun.io/viewer
  • Using full set of examples from nightly build: rerun.io/viewer
• The PR title and labels are set such as to maximize their usefulness for the next release's CHANGELOG
• If applicable, add a new check to the release checklist!
• If have noted any breaking changes to the log API in CHANGELOG.md and the migration guide

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[zehiko]

you're suggesting that description is basically and optional metadata field, right? if so, that indeed makes sense to me.