Handle Python 3.10 unsupported opcodes in AST builder

[Dere3046]

Adds handler cases for 7 Python 3.10 opcodes that were previously
unhandled, preventing pycdc from decompiling any module containing
*args/**kwargs calls, extended unpack, dict merge, assert, or
try/except exception matching.

CALL_FUNCTION_EX produces ASTCall with setVar/setKW for
*args/**kwargs
UNPACK_EX uses the existing unpack mechanism
like UNPACK_SEQUENCE
DICT_MERGE stack balancing for {**d} in dict displays
DICT_UPDATE stack balancing for dict accumulator updates
LOAD_ASSERTION_ERROR stack balancing for assert statements
LIST_TO_TUPLE stack balancing for list-to-tuple conversion
JUMP_IF_NOT_EXC_MATCH stack balancing for except type matching

MAP_ADD and SET_ADD intentionally not handled — their comprehension
AST reconstruction triggers block management issues when used with
conditional comprehension expressions.

4 new tests added: test_call_starargs_310, test_unpack_ex_310,
test_assert_310, test_dict_merge_310. All 84 upstream tests pass.