Support for prof2's sparse database

[laksono]

Branch: pr-metadb-refactor
The document of the emerging sparse database is:
https://github.com/HPCToolkit/hpctoolkit/blob/pr-metadb-refactor/doc/FORMATS.md

With the new database layout:

database/
|-- FORMATS.md     This file
|-- metrics/       Taxonomic metric descriptions for analysis presentations
|   |-- METRICS.yaml.ex  Documentation for the metric taxonomy YAML format
|   `-- default.yaml     Default metric taxonomy, suitable for most cases
|-- meta.db        Properties of the measured application execution
|-- profile.db     Performance measurements arranged by application thread
|-- cct.db         Performance measurements arranged by calling context
|-- trace.db       Time-centric execution traces
`-- src/           Relevant application source files

[laksono]

Done (2022.01.21):

• profile.db
• cct.db
• trace.db

To do:

• meta.db
• METRICS.yaml
• Optimize the creation of bottom-up and flat trees

[blue42u]

This repository has moved to GitLab, please continue this issue there.