refactor(file-uploader): use relative units for file-uploader

Author: spliffone

playwright/snapshots/si-file-uploader.spec.ts-snapshots/si-file-uploader--si-file-uploader--added-element-examples-chromium-dark-linux.png

@@ -48,7 +48,7 @@
             </div>
           } @else {
             <div class="position-relative mt-1 mb-5">
-              <div class="position-absolute end-0 mt-n6">{{ file.progress }} %</div>
+              <div class="position-absolute end-0 progress-value">{{ file.progress }} %</div>
               <si-progressbar
                 height="small"
                 [value]="file.progress"

playwright/snapshots/si-file-uploader.spec.ts-snapshots/si-file-uploader--si-file-uploader--added-element-examples-chromium-light-linux.png

@@ -24,7 +24,10 @@
   display: flex;
   justify-content: center;
   flex-direction: column;
-  block-size: map.get(variables.$spacers, 8) + map.get(variables.$spacers, 9);
+}
+
+.progress-value {
+  inset-block-start: -1lh;
 }
 
 .file {