feat: Theming - Spectrum Provider (#1582)

In this PR:
- First pass of mapping Spectrum dark theme variables to DH theme
variables
- Added Spectrum components that are being used by DH UI to the
styleguide
- Added some navigation to styleguide
- Added a Playwright config for Firefox to fix an issue where no
pointers were detected in `'(any-pointer: fine)'` media queries

resolves #1543

Author: bmingles

.gitignore

@@ -32,6 +32,7 @@ yarn-debug.log*
 yarn-error.log*
 
 css
+!__mocks__/css
 
 tsconfig.tsbuildinfo
 packages/*/package-lock.json

__mocks__/css/mock-theme-dark-components.js

@@ -0,0 +1 @@
+module.exports = 'mock-theme-dark-components';

__mocks__/css/mock-theme-dark-palette.js

@@ -0,0 +1 @@
+module.exports = 'mock-theme-dark-palette';

__mocks__/css/mock-theme-dark-semantic-editor.js

@@ -0,0 +1 @@
+module.exports = 'mock-theme-dark-semantic-editor';

__mocks__/css/mock-theme-dark-semantic-grid.js

@@ -0,0 +1 @@
+module.exports = 'mock-theme-dark-semantic-grid';

__mocks__/css/mock-theme-dark-semantic.js

@@ -0,0 +1 @@
+module.exports = 'mock-theme-dark-semantic';

__mocks__/css/mock-theme-light-palette.js

@@ -0,0 +1 @@
+module.exports = 'mock-theme-light-palette';

__mocks__/css/mock-theme-spectrum-alias.module.js

@@ -0,0 +1,3 @@
+module.exports = {
+  'dh-spectrum-alias': 'mock-dh-spectrum-alias',
+};

__mocks__/css/mock-theme-spectrum-overrides.module.js

@@ -0,0 +1,3 @@
+module.exports = {
+  'dh-spectrum-overrides': 'mock-dh-spectrum-overrides',
+};

__mocks__/css/mock-theme-spectrum-palette.module.js

@@ -0,0 +1,3 @@
+module.exports = {
+  'dh-spectrum-palette': 'mock-dh-spectrum-palette',
+};