Add environment variables to signal feature and version to the CLI

This PR ensures environment variables are set before any invocation of
the CLI.  Here is a list of vars that are set:

https://github.com/github/codeql-coreql-team/issues/1124#issuecomment-852463521

This ensures the CLI knows the features and versions of the containing
actions/runner.

Additionally:

- Fix the user agent so that it more closely aligns with user agent
  spec
- Refactor environment variable initialization so that it all happens in
  one place and call.
- Move Mode, getRequiredEnvParam, setMode, getMode out of actions-util
  and into util. actions-util is meant for utils only called by the
  action, not the runner.

The `prepareLocalRunEnvironment()` method is most likely deprecated and
should be removed. I originally added it because I had a way of working
where I would run the action from my local machine to test out changes,
but this was always a little flaky. So, I no longer use this way of
working. I will probably remove it soon.

lib/autobuild-action.js

@@ -12,9 +12,12 @@ const actions_util_1 = require("./actions-util");
 const autobuild_1 = require("./autobuild");
 const config_utils = __importStar(require("./config-utils"));
 const logging_1 = require("./logging");
+const util_1 = require("./util");
+// eslint-disable-next-line import/no-commonjs
+const pkg = require("../package.json");
 async function sendCompletedStatusReport(startedAt, allLanguages, failingLanguage, cause) {
     var _a, _b;
-    actions_util_1.setMode(actions_util_1.Mode.actions);
+    util_1.initializeEnvironment(util_1.Mode.actions, pkg.version);
     const status = failingLanguage !== undefined || cause !== undefined
         ? "failure"
         : "success";
@@ -31,11 +34,10 @@ async function run() {
     const startedAt = new Date();
     let language = undefined;
     try {
-        actions_util_1.prepareLocalRunEnvironment();
         if (!(await actions_util_1.sendStatusReport(await actions_util_1.createStatusReportBase("autobuild", "starting", startedAt)))) {
             return;
         }
-        const config = await config_utils.getConfig(actions_util_1.getTemporaryDirectory(), logger);
+        const config = await config_utils.getConfig(util_1.getTemporaryDirectory(), logger);
         if (config === undefined) {
             throw new Error("Config file could not be found at expected location. Has the 'init' action been called?");
         }