(NFC) SchemaStructure.php - Fix up mismatch between stored+generated code

(NFC) SchemaStructure.php - Fix up mismatch between stored+generated code

Overview
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The class `CRM_Core_I18n_SchemaStructure` is autogenerated via GenCode, and it is also commited to git.
The two forms don't match because of the recent code-style cleanup.

Before
------

After running GenCode, there appears to be uncommitted changes in `CRM_Core_I18n_SchemaStructure`.
The changes indicate a reversion in code-style (e.g. `null` vs `NULL`; some whitespace).

After
-----

GenCode produces output which matches the recent cleanup.

Comments
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Fixing `null` / `NULL` was easy. However, the whitespace mismatch was more subtle -- because the
`PHP_Beautifier` was messing it up. To resolve, I disabled `PHP_Beautifier` for this file, and fixed
the underlying templates to generate well-formed code.

The output of the process matches the existing code; therefore, the change
have no functional impact (NFC).  You can see this by running `setup.sh` and
checking the `git status`.