Spacy v3 compatibility

[buhrmann]

Updates:

• use of component factory
• simplifies span merging using the PhraseMatchers as_spans parameter
• fixed edge case of overlapping spans using the built-in filter_spans function
• formats with black, as suggested in spaCy contribution guidelines (now uses double quotes by default, not sure if this is configured differently in spaCy, couldn't find any corresponding configuration)
• updates all tests and adds test from Fix span merging explosion/spacymoji#8
• updates docs with new API

To Do:

• a couple of more edge cases as mentioned in various issues in the upstream repo