lint(gui): outline generate buttons

gui/src/components/tab/Img2Img.tsx

@@ -63,7 +63,7 @@ export function Img2Img() {
         }}
       />
       <UpscaleControl />
-      <Button onClick={() => upload.mutate()}>Generate</Button>
+      <Button variant='outlined' onClick={() => upload.mutate()}>Generate</Button>
     </Stack>
   </Box>;
 }

gui/src/components/tab/Inpaint.tsx

@@ -161,7 +161,7 @@ export function Inpaint() {
       </Stack>
       <OutpaintControl />
       <UpscaleControl />
-      <Button onClick={() => upload.mutate()}>Generate</Button>
+      <Button variant='outlined' onClick={() => upload.mutate()}>Generate</Button>
     </Stack>
   </Box>;
 }

gui/src/components/tab/Txt2Img.tsx

@@ -65,7 +65,7 @@ export function Txt2Img() {
         />
       </Stack>
       <UpscaleControl />
-      <Button onClick={() => generate.mutate()}>Generate</Button>
+      <Button variant='outlined' onClick={() => generate.mutate()}>Generate</Button>
     </Stack>
   </Box>;
 }

gui/src/components/tab/Upscale.tsx

@@ -46,7 +46,7 @@ export function Upscale() {
         });
       }} />
       <UpscaleControl />
-      <Button onClick={() => upload.mutate()}>Generate</Button>
+      <Button variant='outlined' onClick={() => upload.mutate()}>Generate</Button>
     </Stack>
   </Box>;
 }