Argdcls

* Type hinting in `load` 24
* Remove dynamic params 27

16 Use `ValueError` to validate inputs

Restore supported Python versions to `^3.8`

Python3.10 is removed from supported python version

Change param signatures

|| `param` | `param` | `+param` | `++param` |
|:---|:---:|:---:|:---:|:---:|
|w/o default value|OK|OK|Error|OK|
|w/ default value|Error|OK|Error|OK|
|not dfined|Error|Error|OK|OK|

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