Analyze: Improve log grouping and log the analysis summary in its own group

As produced by npm ci && npm run removeNPMAbsolutePaths.

Fix grouping of the analysis logs, so that custom query logs also get grouped.
Capture the stdout of codeql database analyze, which contains the analysis summary
from summary and diagnostic queries.
Log this output in its own group, along with the baseline computed in the Action.

Add the first changelog entry

(Adding the changelog itself.)

Add a changelog

Co-authored-by: Aditya Sharad <6874315+adityasharad@users.noreply.github.com>

Adds an empty changelog file and a reminder to update it when opening
pull requests.

Also, adds a 1.0.0 version number in the package.json, which is what
we _could_ use for version numbering.

Use `--build`

Update CodeQL bundle to 20210517 / 2.5.5

Add warnings about CLI hack to codeql.ts

These warnings refer to a hack that was added to the CLI in
https://github.com/github/semmle-code/pull/39335

They can be removed again once the CLI has a more principled way for
the CLI to recognize that it's being invoked by the runner/action.

Add a tasks.json

Change include path for lines of code counting

Previously, we were always using `**` in the include path. the
effect of this was to always count lines in the entire
repository unless explicitly added to the paths-ignore. This
was incorrect behaviour. Now we only using `**` if the include
path is otherwise empty.

Use the prefix id for keying into metrics rules

Fixes a bug where we were looking for incorrect keys for metrics rules.
Previously, we were using full language names in the keys. Now, we use
the short language names in the metric ids. This is done through a
simplification of the code.

Also, this change does two smaller things:

1. Prints out the baseline count to the logs
2. Adds the `assertNever` function to ensure we never miss a case in
   a switch statement. This function is borrowed from vscode-codeql.

Update loc count library

This is just a helpful way to ensure you can run `tsc --watch` from
inside vscode.

This version will count lines of code in each file serially. It still
runs all file system operations asynchronously. The only difference now
is that it will only count one file at a time. It is slower, but it
is able to count large repositories without running out of memory.

Output environment file for Windows