[ENH] Support multiple input formats

[hadarsharon]

Is your feature request related to a problem? Please describe.
To compare dataframes properly, we need to support multiple input formats and methods of getting the dataframes for comparison.

Describe the solution you'd like
I'd like the dataframes to be passed either as existing objects in memory, or to be read from a file (i.e. pass a URI and compars will load the dataframe(s) for you)

Additional context
Preferably, and for starters, we should support most (if not all) formats used by the following libraries, to lay the basis for being "bear-agnostic":

• pandas
• polars
• pyspark