This commit merges the two vectors of specifiers into a single one introducing
the concept of a "TestMode" which is a tri-state enum specifying how a specifier
is to be tested (as documentation, as an executable module or as both).
This is determined during the collection phase and determines how a specifier
will be executed based on how the specifier was collected (directly or not) and
if it has an eligible media_type when fetched.
For example "deno test README.md" is marked as documentation because, while it
is a direct inclusion it is not an executable media type therefore will only
have the fenced code blocks that can be parsed from it tested.
This commit adds support for running test in parallel.
Entire test runner functionality has been rewritten
from JavaScript to Rust and a set of ops was added to support reporting in Rust.
A new "--jobs" flag was added to "deno test" that allows to configure
how many threads will be used. When given no value it defaults to 2.
