Fuzzy Index: Index text for performing fuzzy search

This class can index text for performing fuzzy search.

It can process a list of text strings and build a database that indexes snippets of those strings and the locations where they appear.

The class can also search for given keywords and returns the locations of the indexed strings where the best matching text appears.

It uses SQLite to store the indexed text database, but the class can be extended to use a different database type.

It uses certain heuristics to extract the snippets from the indexed text. These heuristics are implemented as separate classes that can be used interchangeably.