Add a note to the UI about final database URL

All database URLs will have a path appended to the user provided URL. This is not obvious to the user in the UI. This can lead to the user incorrectly adding the path themselves.

- Gremlin - `{database-url}/gremlin`
- openCypher - `{database-url}/opencypher`
- SPARQL - `{database-url}/sparql`

## Potential Solution

We should add a note in the UI that shows what the final URL will be with the path appended. This should be in a `FieldDescription` below the input field. Something like

> The URL that will be used is `https://my-database.com:8182/sparql`

## Related issues

- #23
- #1326

Locate the database URL input in the UI and inspect how its FieldDescription is rendered. Add a note showing the final URL with the appropriate /gremlin, /opencypher, or /sparql path appended, then verify the displayed examples for each database type.

Written by the indexing model from the issue text.