thread view: Add more UI improvements (#36750)

Release Notes:

- N/A

assets/icons/attach.svg

@@ -0,0 +1,3 @@
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M7.37288 4.48506L7.43539 10.6638C7.43539 10.9365 7.54373 11.1981 7.73655 11.3909C7.92938 11.5837 8.19092 11.6921 8.46362 11.6921C8.73632 11.6921 8.99785 11.5837 9.19068 11.3909C9.38351 11.1981 9.49184 10.9366 9.49184 10.6638L9.42933 4.48506C9.42933 3.93975 9.2127 3.41678 8.82711 3.03119C8.44152 2.6456 7.91855 2.42898 7.37324 2.42898C6.82794 2.42898 6.30496 2.6456 5.91937 3.03119C5.53378 3.41678 5.31716 3.93975 5.31716 4.48506L5.37968 10.6384C5.37636 11.0455 5.45368 11.4492 5.60718 11.8263C5.76067 12.2034 5.98731 12.5463 6.27401 12.8354C6.56071 13.1244 6.9018 13.3538 7.27761 13.5104C7.65341 13.667 8.0565 13.7476 8.46362 13.7476C8.87073 13.7476 9.27382 13.667 9.64963 13.5104C10.0254 13.3538 10.3665 13.1244 10.6532 12.8354C10.9399 12.5463 11.1666 12.2034 11.3201 11.8263C11.4736 11.4492 11.5509 11.0455 11.5476 10.6384L11.485 4.48506" stroke="black" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round"/>
+</svg>

assets/icons/tool_think.svg

@@ -1,3 +1,3 @@
 <svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
-<path d="M9.95231 10.2159C10.0803 9.58974 9.95231 9.57261 10.9111 8.46959C11.4686 7.82822 11.8699 7.09214 11.8699 6.27818C11.8699 5.28184 11.4658 4.32631 10.7467 3.62179C10.0275 2.91728 9.05201 2.52148 8.03492 2.52148C7.01782 2.52148 6.04239 2.91728 5.32319 3.62179C4.604 4.32631 4.19995 5.28184 4.19995 6.27818C4.19995 6.9043 4.32779 7.65565 5.1587 8.46959C6.11744 9.59098 5.98965 9.58974 6.11748 10.2159M9.95231 10.2159V12.2989C9.95231 12.9504 9.41327 13.4786 8.7482 13.4786H7.32165C6.65658 13.4786 6.11744 12.9504 6.11744 12.2989L6.11748 10.2159M9.95231 10.2159H8.03492H6.11748" stroke="black" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round"/>
+<path d="M9.9526 10.2625C10.0833 9.62316 9.9526 9.60566 10.9315 8.47946C11.5008 7.82461 11.9105 7.07306 11.9105 6.242C11.9105 5.22472 11.4979 4.2491 10.7637 3.52978C10.0294 2.81046 9.03338 2.40634 7.99491 2.40634C6.95644 2.40634 5.96051 2.81046 5.22619 3.52978C4.49189 4.2491 4.07935 5.22472 4.07935 6.242C4.07935 6.88128 4.20987 7.64842 5.05825 8.47946C6.03714 9.62442 5.90666 9.62316 6.03718 10.2625M9.9526 10.2625V12.3893C9.9526 13.0544 9.40223 13.5937 8.72319 13.5937H7.26665C6.58761 13.5937 6.03714 13.0544 6.03714 12.3893L6.03718 10.2625M9.9526 10.2625H7.99491H6.03718" stroke="black" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round"/>
 </svg>