This reverts commit 43d0664.

This commit adds the packs and queries from the actions input to the
config file used by the CodeQL CLI.

When the `+` is used, the actions input value is combined with the
config value and when it is not used, the input value overrides the
config value.

This commit also adds a bunch of integration tests for this feature.
In order to avoid adding too many new jobs, all of the tests are
run sequentially in a single job (matrixed across relevant operating
systems and OSes).

When the codescanning config is being used by the CLI, there is a
single query suite that is generated that contains all queries to be
run by the analysis. This is different from the traditional way, where
there are potentially three query suites: builtin, custom, and packs.

We need to ensure that when the codescanning config is being used,
only a single call to run queries is used, and this call uses the
single generated query suite.

Also, this commit changes the cutoff version for codescanning config to
2.10.1. Earlier versions work, but there were some bugs that are only
fixed in 2.10.1 and later.

This makes some syntax in tests somewhat simpler.

…ig-files

…config-files