Bugfix/key valuerror after copy

[agentd00nut]

Bug Explanation

Trying to copy an ImagePreset is currently failing. _DEFAULT has settings for legacy, uncond_scale, cfg_rescale, and noise_schedule. _TYPE_MAPPING does not have those entries.

This causes us to hand in settings (pulled from default) during copy that trigger during setitem

    def __setitem__(self, key: str, value: Any):
        if key not in self._TYPE_MAPPING:  # _DEFAULT's that have no _TYPE_MAPPING make this explode during .copy()!
            raise ValueError(f"'{key}' is not a valid setting")

Solution

• Updating _TYPE_MAPPING with entries for the _DEFAULT's that it was missing.
• Adding a preset.copy() line during tests to prevent setting _DEFAULT's without a corresponding a _TYPE_MAPPING
• Also apparently the pre-commit thought _high_level.py needed some reformatting....