Add support for reading bam files

This adds a ReadParser class which abstracts away fastq/fasta vs bam/sam files and allows for translating bam files

PR checklist

[x] This comment contains a description of changes (with reason)
[x] If you've fixed a bug or added code that should be tested, add tests!
[x] Ensure the test suite passes with pytest . (command to run: pytest or make coverage if you want to see which lines don't have tests yet)
[x] Make sure your code is linted and autoformatted using black (black . --check).
[x] Documentation in usage.md is updated
[x] README.md is updated