[Impeller] Reland move more files to core.

[dnfield]

Relands #40801
See #40811
Includes changes in #40810

This got reverted due to an unhappy merge missing an include in a modified file. Fixed that up and it should build now.

[zanderso]

There was an unanswered question from @bdero on the original PR. Was that discussed out-of-band?

[zanderso]

What's this?

[dnfield]

This is how all the other otherwise header-only TUs are handled in impeller

[dnfield]

Due to github magic I missed that question. The answer (I'll add it there too), is that ResourceBinder's real purpose is to make sure that the generated code can depend exclusively on core and not on renderer, because renderer has shaders in it now.

If we add some other command type that's radically different from ComputeCommand and Command, we can add a different type that's like ResourceBinder but more suited to that new (currently hypothetical) command.

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Changes reported for pull request #40812 at sha a803398

[auto-submit]

auto label is removed for flutter/engine, pr: 40812, Failed to merge pr#: 40812 with Pull request could not be merged: Pull Request is not mergeable.

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Changes reported for pull request #40812 at sha 0a11849