startop: Add script to analyze block I/O from an ftrace file

Adds a simple python parser to convert .ftrace file into
sqlite3 database.

The rest of the analysis logic is done through a series of SQL
commands that build tables/views/select queries.

Bug: 134705245
Test: trace_analyzer some_ftrace_file.trace tmp_file.db
Change-Id: I25274e25a0ab1f091ae4e6161e6726e006e346a5