Major project refactor

[tonykchen]

Issue #, if available:
#14

Description of changes:

• Reorganized and consolidated a majority of the modules to simplify the codebase.
• Added a --filter CLI argument to run specific tests.
• Refactored the tests configuration from a list to a mapping, where the test name serves as the key. This allows us to fetch the tests more efficiently when --filter is specified.
• Implemented logging for evaluator token I/O.
• Added provisioned throughput support for evaluator models (will implement PT support for targets in a later PR).
• Remove Claude 3 Haiku as an available evaluator model for the initial release.
• Implemented target and evaluator factories which encapsulates logic needed to create these objects.
• Updated user documentation with changes made.

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[sharonxiaohanli]

LGTM