Frontend: Extract CSS imports into files (#94655)

* build(webpack): extract css imports into files including node_modules

* feat(webassets): add cssfiles to entrypoint assets for extracted css files

* feat(views): add entrypoint css link tags to html templates

* feat(webassets): set CDN prefix for CSS files

* test(webassets): trim down sample-assets-manifest, fix failing snapshot tests

* Update pkg/api/webassets/webassets_test.go

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

* build(webpack): remove css module loader

---------

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

pkg/api/dtos/index.go

@@ -39,9 +39,11 @@ type IndexViewData struct {
 type EntryPointAssets struct {
 	ContentDeliveryURL string            `json:"cdn,omitempty"`
 	JSFiles            []EntryPointAsset `json:"jsFiles"`
+	CSSFiles           []EntryPointAsset `json:"cssFiles"`
 	Dark               string            `json:"dark"`
 	Light              string            `json:"light"`
 	Swagger            []EntryPointAsset `json:"swagger"`
+	SwaggerCSSFiles    []EntryPointAsset `json:"swaggerCssFiles"`
 }
 
 type EntryPointAsset struct {
@@ -59,7 +61,13 @@ func (a *EntryPointAssets) SetContentDeliveryURL(prefix string) {
 	for i, p := range a.JSFiles {
 		a.JSFiles[i].FilePath = prefix + p.FilePath
 	}
+	for i, p := range a.CSSFiles {
+		a.CSSFiles[i].FilePath = prefix + p.FilePath
+	}
 	for i, p := range a.Swagger {
 		a.Swagger[i].FilePath = prefix + p.FilePath
 	}
+	for i, p := range a.SwaggerCSSFiles {
+		a.SwaggerCSSFiles[i].FilePath = prefix + p.FilePath
+	}
 }