Fix ICSS syntax in stylesheets (#10511)

Author: Christiaan van Bemmel

packages/react-scripts/config/webpack.config.js

@@ -518,6 +518,9 @@ module.exports = function (webpackEnv){
 sourceMap: isEnvProduction
  ? shouldUseSourceMap
  : isEnvDevelopment,
+modules: {
+compileType: 'icss',
+},
 }),
 // Don't consider CSS imports dead code even if the
 // containing package claims to have no side effects.
@@ -535,6 +538,7 @@ module.exports = function (webpackEnv){
  ? shouldUseSourceMap
  : isEnvDevelopment,
 modules: {
+compileType: 'module',
 getLocalIdent: getCSSModuleLocalIdent,
 },
 }),
@@ -551,6 +555,9 @@ module.exports = function (webpackEnv){
 sourceMap: isEnvProduction
  ? shouldUseSourceMap
  : isEnvDevelopment,
+modules: {
+compileType: 'icss',
+},
 },
 'sass-loader'
 ),
@@ -571,6 +578,7 @@ module.exports = function (webpackEnv){
  ? shouldUseSourceMap
  : isEnvDevelopment,
 modules: {
+compileType: 'module',
 getLocalIdent: getCSSModuleLocalIdent,
 },
 },