dillon1000/react

[compiler] More precise errors for invalid import/export/namespace statements (#33748)

import, export, and TS namespace statements can only be used at the
top-level of a module, which is enforced by parsers already. Here we add
a backup validation of that. As of this PR, we now have only major
statement type (class declarations) listed as a todo.

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* #33753
* #33752
* #33751
* #33750
* __->__ #33748