Explore Traces: Values is not quoted when manually written into query builder dropdown

### What happened? I went to Explore with Traces datasource. I selected one of the span tags values and I wrote my own value into the dropdown. The query it built didn't quote that string value so the query had invalid syntax.  ### What did you expect to happen? I expect the "query builder" to build valid queries (and quote the values I write). ### Did this work before? I don't think so. ### How do we reproduce it? 1. Go to explore 2. Select a Tempo datasource 3. Select one attribute in the span search box 4. Write your own value ### Is the bug inside a dashboard panel? No, it's in explore. ### Environment (with versions)? Grafana: internal ops OS: Mac OS Browser: Arc ### Grafana platform? I use Grafana Cloud ### Datasource(s)? Tempo