Align account_do with core localization structure

Add CreateChart defaults for the Dominican receivable and payable accounts, following the pattern used by official Tryton localization modules.

Register the chart wizard extension, add core-style documentation files, and protect the structure with transactional and static tests.

doc/design.rst

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+Design
+======
+
+``account_do`` is a base accounting localization module. It follows the same
+shape as Tryton chart modules such as ``account_fr``, ``account_be``, and
+``account_syscohada``:
+
+* chart, tax, tax code, and tax rule data are declarative XML records;
+* Python code extends existing account models only where Dominican metadata or
+  chart setup defaults are needed;
+* the chart creation wizard proposes the Dominican receivable and payable
+  control accounts when the Dominican chart is selected;
+* fiscal report box mapping remains outside this module and is owned by
+  reporting modules such as ``dgii_reports``.
+
+The module deliberately avoids replacing posting, tax computation, or invoice
+logic from Tryton's ``account`` module. Complementary Dominican modules should
+consume the accounts, taxes, tax codes, and metadata defined here.