Revert introduction of tailwind (#2109)

After many days invested in making tailwind work in the SCM-Manager environment as well as a long discussion last week, we have decided not to move further with tailwind, but still keep adding new, independent modules for frontend components. Tailwind simply overcomplicated our build pipeline because bulma was already part of the api and the two were incompatible on several occasions. Styling will continue to be guided by bulma and all parts related to tailwind are removed. We therefore continue the trend of focusing on improving our existing stack rather than adding further complexity.

scm-ui/ui-buttons/docs/introduction.stories.mdx

@@ -35,22 +35,22 @@ There are four variants available to each of the three button types, varying in
   <tbody>
   <tr>
     <td>Very High</td>
-    <td><Button variant="signal" className="w-full">Signal</Button></td>
+    <td><Button variant="signal">Signal</Button></td>
     <td>Destructive actions</td>
   </tr>
   <tr>
     <td>High</td>
-    <td><Button variant="primary" className="w-full">Primary</Button></td>
+    <td><Button variant="primary">Primary</Button></td>
     <td>Form submit</td>
   </tr>
   <tr>
     <td>Normal</td>
-    <td><Button variant="secondary" className="w-full">Secondary</Button></td>
+    <td><Button variant="secondary">Secondary</Button></td>
     <td>Cancel action in dialog</td>
   </tr>
   <tr>
     <td>Low</td>
-    <td><Button variant="tertiary" className="w-full">Tertiary</Button></td>
+    <td><Button variant="tertiary">Tertiary</Button></td>
     <td>Circumstantially relevant action on page with many actionable elements</td>
   </tr>
   </tbody>