Improve edge-cases and warn on ambiguity for Rgba32 datatype

[jleibs]

What

• Resolves: LineStrips3D ignores color if num_strips divisible by four or equals three #8035
• Makes it so lists of ints are generally assumed to be packed colors unless they are length 3 or 4
• Warns when passing a length 3 or 4 list of colors that uses values outside of the u8 range.
• Preserves the old functionality when explicitly passing an np.array of the right type.

The previous offending code:

import rerun as rr

rr.init("rerun_example_colorbad", spawn=True)

point = [[0, 0, 0]]
colors = [0x00FF00FF]  # green

for n in range(30):
    rr.log("points3d", rr.Points3D(positions=point * n, colors=colors * n))

Now works, but produces a warning:

/home/jleibs/colorbad.py:11: RerunWarning: Ambiguous input for colors of length 4. If using 0xRRGGBBAA values, please wrap as np.array with dtype=np.uint32
  rr.log("points3d", rr.Points3D(positions=point * n, colors=colors * n))

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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[github-actions]

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