Improve custom XPath support

[refortie]

Describe the Bug with repro steps

Better support through stuff like syntax highlighting, larger text box, and other nice to haves

Screenshots or Videos

No response

Version

Dev

Additional context

No response

AB#24187925

[azure-boards[bot]]

❌ There was a problem linking to Azure Boards work item(s):

• 24187925

Please check the IDs and try again using the AB# syntax. Learn more

[azure-boards[bot]]

❌ There was a problem linking to Azure Boards work item(s):

• 24187925

Please check the IDs and try again using the AB# syntax. Learn more

[azure-boards[bot]]

❌ There was a problem linking to Azure Boards work item(s):

• 24187925

Please check the IDs and try again using the AB# syntax. Learn more

[azure-boards[bot]]

❌ There was a problem linking to Azure Boards work item(s):

• 24187925

Please check the IDs and try again using the AB# syntax. Learn more