Cody: Fix button border display issue & update webview UI toolkit (#51726)

Close https://github.com/sourcegraph/sourcegraph/issues/51719
Unblock https://github.com/sourcegraph/sourcegraph/pull/51246

Thanks @eseliger and @philipp-spiess for the help with [upgrading the
packages](https://sourcegraph.slack.com/archives/C052G9Y5Y8H/p1683728783413159)
🙇

## Issues

There was an issue with VS Code Webview buttons displaying a light
border due to max-width set to 300 in the upstream package, which was
then fixed in
https://github.com/microsoft/vscode-webview-ui-toolkit/issues/384


![image](https://github.com/sourcegraph/sourcegraph/assets/68532117/3143b960-3008-4f31-b409-39aafa7ad8ab)

Text is squeezed to the side due to max width issue:

![image](https://github.com/sourcegraph/sourcegraph/assets/68532117/7e77d525-6f00-4f77-8d5a-18bf06142edb)

## Fixs

After updating the package, there is still a border for the height, but
the width constrain has been removed which solve the issue where the
text is squeezed to the side:
<img width="557" alt="image"
src="https://github.com/sourcegraph/sourcegraph/assets/68532117/b07cbd16-2ae5-46e7-bca9-8d1459fc076c">

Overriding the border color manually worked:

<img width="616" alt="image"
src="https://github.com/sourcegraph/sourcegraph/assets/68532117/72afcb1d-cf4a-4785-83fc-6d99438ddb71">


## Test plan

<!-- All pull requests REQUIRE a test plan:
https://docs.sourcegraph.com/dev/background-information/testing_principles
-->

Package updated and working fine locally. See screenshots above

client/cody/CHANGELOG.md

@@ -8,6 +8,8 @@ All notable changes to Sourcegraph Cody will be documented in this file.
 
 ### Fixed
 
+- UI bug that capped buttons at 300px max-width with visible border [pull/51726](https://github.com/sourcegraph/sourcegraph/pull/51726)
+
 ### Changed
 
 ## [0.1.1]

client/cody/webviews/index.css

@@ -14,6 +14,8 @@
     color: var(--vscode-sideBar-foreground);
     background-color: var(--vscode-sideBar-background);
     height: 100%;
+    /* Override VS Code Webview Toolkit elements */
+    --border-width: none;
 }
 
 html,

package.json

@@ -221,6 +221,7 @@
     "@types/testing-library__jest-dom": "5.9.5",
     "@types/uuid": "8.0.1",
     "@types/vscode": "^1.76.0",
+    "@types/vscode-webview": "^1.57.1",
     "@types/webpack-bundle-analyzer": "^4.6.0",
     "@types/webpack-stats-plugin": "^0.3.2",
     "@types/yauzl": "^2.9.2",
@@ -395,7 +396,7 @@
     "@visx/text": "2.10.0",
     "@visx/voronoi": "^2.10.0",
     "@vscode/codicons": "^0.0.29",
-    "@vscode/webview-ui-toolkit": "^0.9.0",
+    "@vscode/webview-ui-toolkit": "^1.2.2",
     "agent-base": "6.0.2",
     "ajv": "^8.6.3",
     "ajv-formats": "^2.1.1",