Replacing global themed sass-vars to css-vars (#4322)

* generating css-vars
* convert all global / theme sass vars to css vars with available default theme colors
* added missing colors to dark lens theme

build/build_theme_vars.ts

@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2021 OpenLens Authors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+import fs from "fs-extra";
+import path from "path";
+import defaultBaseLensTheme from "../src/renderer/themes/lens-dark.json";
+
+const outputCssFile = path.resolve("src/renderer/themes/theme-vars.css");
+
+const banner = `/* 
+    Generated Lens theme CSS-variables, don't edit manually.
+    To refresh file run $: yarn run ts-node build/${path.basename(__filename)}
+*/`;
+
+const themeCssVars = Object.entries(defaultBaseLensTheme.colors)
+  .map(([varName, value]) => `--${varName}: ${value};`);
+
+const content = `
+${banner}
+
+:root {
+${themeCssVars.join("\n")}
+}
+`;
+
+// Run
+console.info(`"Saving default Lens theme css-variables to "${outputCssFile}""`);
+fs.ensureFileSync(outputCssFile);
+fs.writeFile(outputCssFile, content);