Declaration of properties, attributes and command type with typing hints

Closes #53 (closed) and #373 (closed)

This MR makes possible to declare type of properties, attributes and commands in high-API servers with type hint, if server executed with python >= 3.9. E.g.:

    host: str = device_property()

or

    @command
    def set_and_check_voltage(self, voltage_to_set: float) -> float:
        device.set_voltage(voltage_to_set)
        return device.get_voltage()

For the attributes type hint can be done at assignment (like property), or in the read/write method (like command).

    voltage: float = attribute()

    current = attribute()

    def read_current(self) -> float:
        return 10

At any cases the prority to obtain type is:

1. dtype kword
2. assignment
3. read method
4. write method

To define SPECTRUM and IMAGE attributes/properties/commands one can use list[type] or tuple[type]. In case of tuple the dimensions can be also specified from type hint: tuple[type, type], or tuple[tuple[type, type], tuple[type, type]]

Status of what done:

• static attributes
• dynamic attributes
• static commands
• dynamic commands
• properties
• documentation

Changes in the code:

1. Properties:

dtype kword made optional with default value None and later. At the server creation if dtype is None we try to pick it from the Class.__annotations__

2. Attributes: Added 2 additional filed to AttrData: has_dtype_kword, has_size_kword, which are False by default, and they set to True if users specify type and size in kwords (default behavior, as it was before). At the server creation if has_dtype_kword is False we try to pick it from the Class.__annotations__ and then from read/write_method.__annotations__.

In case of dynamic attribute, we try to get info during methods patching. Due to we cannot do Class.__annotations__, since attributes arr defined within the function and their assignment hints are not saved, so we can pick only from methods. I also had to modify slightly the logic of AttrData class in a way, that self.attr_args are now created at the last moment - since we post-updating dtype and format after init of AttrData

3. We just look to the annotation of function. Again, with the priority to the standard kwords.

4. There is additional parce_type_hint method in utils.py, that converts type hint to "tango format" of dtype

5. tests of all possible combinations were added

6. Tried to explain everything in docs.