Use base styling for MRVA results font

It's been pointed out that MRVA results are hard to read as the font is
small and narrowly spaced. It also doesn't match the font type normally
used in source files.

We can instead switch to using the font-family used by VS Code itself and
increase the font size from `x-small` to `small` for code snippets.

Author: elenatanasoiu

extensions/ql-vscode/src/remote-queries/view/FileCodeSnippet.tsx

@@ -24,8 +24,8 @@ const getSeverityColor = (severity: ResultSeverity) => {
 const replaceSpaceAndTabChar = (text: string) => text.replaceAll(' ', '\u00a0').replaceAll('\t', '\u00a0\u00a0\u00a0\u00a0');
 
 const Container = styled.div`
-  font-family: ui-monospace, SFMono-Regular, SF Mono, Menlo, Consolas, Liberation Mono, monospace;
-  font-size: x-small;
+  font-family: var(--vscode-editor-font-family);
+  font-size: small;
 `;
 
 const TitleContainer = styled.div`
@@ -46,7 +46,7 @@ const CodeContainer = styled.div`
 `;
 
 const MessageText = styled.div`
-  font-size: x-small;
+  font-size: small;
   padding-left: 0.5em;
 `;