AgentPython capture external constants.

[Robadob]

import pyflamegpu
import typing
TEST: typing.Final = 5
TEST2: typing.Final = 12
TEST2: typing.Final = math.sqrt(12 * 36)
TEST3: pyflamegpu.constant = 12
TEST4: int = 14

converts to

constexpr auto TEST = 5;
constexpr auto TEST2 = 20.784609690826528;
constexpr auto TEST3 = 12;

todo

• [x] tests
• [x] Do something inside actual codegen() to make global vars constexpr? (if a user passes in a string)
• [x] Replace inspect.get_attributes() (Its python 3.10+, can be emulated via inspect.get_members())

Closes #1144