perf(cdk/table): Optimize a11y role logic in CdkCell.

[kseamon]

1. Uplevels repeated logic to the host CdkTable which does it once instead of n times.
2. Skips setting role=cell in native tables, for which it is already the default (see https://developer.mozilla.org/en-US/docs/Web/HTML/Element/td#technical_summary)

This saves just over a tenth of a millisecond per cell in the native TD case and about a twentieth in other cases. Doesn't sound like much, but it adds up in larger tables.

[crisbeto]

@kseamon can you run yarn approve-api cdk/table and commit the result?

[kseamon]

@kseamon can you run yarn approve-api cdk/table and commit the result?

Done!

[kseamon]

Rejiggered a bit to account for a few internal cases where the table's role was changing between its constructor and the first cell's constructor.

[crisbeto]

@kseamon looks like this needs a rebase and there's a lint failure.

[kseamon]

@kseamon looks like this needs a rebase and there's a lint failure.

Rebased. The internal CL for this (596613799) is already submitted. Is it possible to handle the lint issue in a fast follow PR?

[andrewseguin]

@kseamon Yup no problem, we can merge this and fix the lint issue with an immediate followup PR

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