[Feature] Allow for Semantic Manifest to be retrieved from external location

### Is this your first time submitting a feature request?

- [X] I have read the [expectations for open source contributors](https://docs.getdbt.com/docs/contributing/oss-expectations)
- [X] I have searched the existing issues, and I could not find an existing issue for this feature
- [X] I am requesting a straightforward extension of existing metricflow functionality, rather than a Big Idea better suited to a discussion

### Describe the feature

It looks like in [this PR](https://github.com/dbt-labs/metricflow/pull/605/files), `mf` was changed to instantiate the Semantic Manifest from the dbt project, which requires that commands be executed in the same directory as dbt. This is great for local development! Unfortunately, it *could* make it a bit more difficult for folks doing programmatic use such as within Airflow.

It would be great if you could **also** specify a location that contains the semantic manifest that could be retrieved. This opens up more use cases for folks who may want to invoke MetricFlow from within their pipelines.

### Describe alternatives you've considered

Not allowing this

### Who will this benefit?

Anyone who wants to use MetricFlow in use cases beyond local development.

### Are you interested in contributing this feature?

Sure if it is something that fits in the roadmap.

### Anything else?

_No response_