Adapt yacman v0.9.3

[nsheff]

Draft PR of changes to make pipestat compatible with yacman v0.9.3, in prep for yacman v1

[codecov[bot]]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (6c4797c) 54.51% compared to head (dc47361) 54.56%.

Files	Patch %	Lines
pipestat/pipestat.py	71.42%	2 Missing :warning:
pipestat/backends/file_backend/filebackend.py	90.90%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #147 +/- ## ========================================== + Coverage 54.51% 54.56% +0.05% ========================================== Files 15 15 Lines 2328 2335 +7 ========================================== + Hits 1269 1274 +5 - Misses 1059 1061 +2 ```

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[donaldcampbelljr]

Ok, I think I've got this completed. One thing is that the new functionality is a bit messier to implement:

        self.cfg[CONFIG_KEY] = YAMLConfigManager(
            entries=config_dict, filepath=self.cfg["config_path"]
        )

becomes

        if config_dict is not None:
            self.cfg[CONFIG_KEY] = YAMLConfigManager.from_obj(entries=config_dict)
        elif self.cfg["config_path"] is not None:
            self.cfg[CONFIG_KEY] = YAMLConfigManager.from_yaml_file(filepath=self.cfg["config_path"])
        else:
            self.cfg[CONFIG_KEY] = YAMLConfigManager()