Adopt `readParquet` method to read the whole directory in short and clear way

1. Often parquet dataset is a directory of files that should be read as one dataframe
   pandas:

df = pd.read_parquet("/home/nikita/Desktop/parquet")
print(df)

dataframe, no luck:

val df = DataFrame.readParquet("/home/nikita/Desktop/parquet")
df.print()

Exception in thread "main" java.lang.RuntimeException: Error creating dataset. Could not read schema from '/home/nikita/Desktop/parquet'. Is this a 'parquet' file?: Cannot open for reading: path '/home/nikita/Desktop/parquet' is a directory

We should scan provided directories for parquet files same as pandas

2. Workaround is verbose too

Actual DataFrame code if i need to read list of files:
DataFrame.readParquet(*Path("").listDirectoryEntries().toTypedArray())

Expected:
DataFrame.readParquet(Path("").listDirectoryEntries())

We need Iterable overloads for reading methods

This entire https://ftp.ebi.ac.uk/pub/databases/opentargets/platform/25.03/output/ collection of datasets comes in such format

Start at the DataFrame.readParquet entry point and inspect how a single path is currently handled, along with the Path and Iterable call forms shown in the issue. Define completion as allowing a parquet directory or an Iterable of paths to be read without manually expanding the directory entries, while preserving the existing single-file behavior.