merge inspectorStyle.css and inspectorCommon.css

It seems there is no requirement for these files to be split; they don't
seem to have a logical split and they are both injected into the `body`
element when DevTools runs. If we kept both of these files around, we'd
have to inject them both into the component docs helpers, and deal with
both of them when it comes to figuring out where legacy CSS variables
are defined.

To make it a bit simpler I've merged `inspectorStyle` into
`inspectorCommon`. I went this way because:

* `inspectorCommon.css` is (I think!) a better name than `inspectorStyle.css`
* `inspectorCommon.css` was bigger.

I also drive-by disabled the stylelint `comment-empty-line-before`,
which was forbidding empty lines before any CSS comments; which made the
entire file feel very squashed!

Bug: none
Change-Id: Ifaa834c7bf56291561e2e5cc124c4efd85c3cc56
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2716285
Commit-Queue: Jack Franklin <jacktfranklin@chromium.org>
Reviewed-by: Tim van der Lippe <tvanderlippe@chromium.org>
diff --git a/scripts/component_server/server.js b/scripts/component_server/server.js
index 1ea215f..4564232 100644
--- a/scripts/component_server/server.js
+++ b/scripts/component_server/server.js
@@ -241,11 +241,11 @@
     const fileContents = await fs.promises.readFile(path.join(devtoolsRootFolder, filePath), {encoding: 'utf8'});
     const themeColoursLink = `<link rel="stylesheet" href="${
         path.join(sharedResourcesBase, 'front_end', 'ui', 'themeColors.css')}" type="text/css" />`;
-    const inspectorStyleLink = `<link rel="stylesheet" href="${
-        path.join(sharedResourcesBase, 'front_end', 'ui', 'inspectorStyle.css')}" type="text/css" />`;
+    const inspectorCommonLink = `<link rel="stylesheet" href="${
+        path.join(sharedResourcesBase, 'front_end', 'ui', 'inspectorCommon.css')}" type="text/css" />`;
     const toggleDarkModeScript = `<script type="module" src="${
         path.join(sharedResourcesBase, 'front_end', 'component_docs', 'component_docs.js')}"></script>`;
-    const newFileContents = fileContents.replace('<style>', `${themeColoursLink}\n${inspectorStyleLink}\n<style>`)
+    const newFileContents = fileContents.replace('<style>', `${themeColoursLink}\n${inspectorCommonLink}\n<style>`)
                                 .replace('<script', toggleDarkModeScript + '\n<script');
     respondWithHtml(response, newFileContents);