* refactor(xml): Move textToDom to core/utils/xml.ts
This function being in core/xml.ts was the cause for the last
remaining circular import in core/ (between variables.ts and
xml.ts).
Moving it to utils/xml.ts makes sense anyway, since there is
nothing Blockly-specific about this function.
Fixes#6817.
* fix(closure): Reenable goog.declareModuleId multiple-call check
Reenable an assertion which check to make sure that
goog.declareModuleId is not called more than once in a module
(and which also catches circular imports amongst ES modules, which
are not detected by closure-make-deps).
* chore(tests,demos): Augo-migrate use of textToDom
Testing the migration file entry by auto-migrating all uses of
Blockly.Xml.textToDom to Blockly.utils.xml.textToDom.
* chore(blocks): Manually migrate remaining use of textToDom
Update the one remaining call to textToDom (in blocks/lists.ts)
to the function's new location - also removing the last use of
the Blockly.Xml / core/xml.ts) module from this file.
* docs(xml): Remove unneeded @alias per comments on PR #6818
* fix(imports): Remove unused import
* chore: change goog.module to goog.declareModuleId
* chore: change test helper exports to esmod exports
* chore: change test helpers to use esmodule imports
* chore: convert imports of test helpers to esmodule imports
* chore: convert other imports in tests to esm imports
* fix: make imports use built files
* chore: add blockly imports to a bunch of tests
* fix: reference Blockly.Blocks instead of Blocks'
* fix: properly import generators
* chore: fix lint
* chore: cleanup from rebase
* chore: cleanup from rebase
* chore: fix blocks tests
