Function extract_external_csv

fn extract_external_csv(line: &str, ebml_file: &str) -> Table

When a single “CSV File” line is encountered, this function reads the informational parts, parsed with the pipe character, particularly the external file to reference and read in.

This function returns a Table object, and gets the “array” information from the referenced external file, and the “caption” information from the piped-through text in the single EBML line.

Critical assumption: the external CSV file is in the same folder as the EBML file that references it. This path is passed in as “ebml_file” and parsed within the function as such.