Rename ASTBacktrace to ASTExecutionStack

src/language/PugsParser.cpp

src/language/ast/ASTBuilder.cpp

src/language/ast/ASTExecutionStack.cpp

src/language/ast/ASTExecutionStack.hpp

src/language/ast/ASTNode.hpp

src/language/ast/CMakeLists.txt

src/language/modules/DevUtilsModule.cpp

src/utils/SignalManager.cpp

tests/test_ASTModulesImporter.cpp

tests/test_ASTNode.cpp

tests/test_ASTNodeListProcessor.cpp

tests/test_AffectationProcessor.cpp

tests/test_AffectationToStringProcessor.cpp

tests/test_AffectationToTupleProcessor.cpp

tests/test_ArraySubscriptProcessor.cpp

tests/test_BinaryExpressionProcessor_arithmetic.cpp

tests/test_BinaryExpressionProcessor_shift.cpp

tests/test_BinaryExpressionProcessor_utils.hpp

tests/test_BuiltinFunctionProcessor.cpp