[fidl][cpp] Revert "Table support: fixes"

This reverts commit adc760b5.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> [fidl][cpp] Table support: fixes
> 
> See https://fuchsia-review.googlesource.com/c/garnet/+/223232
> 
> Test: compiles
> Change-Id: I29449947ebb6a114275f46973bc9d461ed7d747c

TBR=ctiller@google.com,pascallouis@google.com

Change-Id: I2067819fadd52cd5c8431177a9d01039ef3234c6
No-Presubmit: true
No-Tree-Checks: true
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