Datasource: Fix storing timeout option as numeric (#35441) (#35481)

#31871 introduced support for configuring timeout in seconds
for HTTP data sources. That had a bug where backend expected
a numeric timeout value where it was actually stored as a
string. This should resolve this by requiring input to be
numbers, storing input as numeric and falling back to string
value if there's no numeric value.

Ref #31871

(cherry picked from commit d15d87db8a)

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

packages/grafana-ui/src/components/DataSourceSettings/DataSourceHttpSettings.tsx

@@ -167,13 +167,14 @@ export const DataSourceHttpSettings: React.FC<HttpSettingsProps> = (props) => {
               <div className="gf-form">
                 <FormField
                   label="Timeout"
+                  type="number"
                   labelWidth={13}
                   inputWidth={20}
                   tooltip="HTTP request timeout in seconds"
                   value={dataSourceConfig.jsonData.timeout}
                   onChange={(event) => {
                     onSettingsChange({
-                      jsonData: { ...dataSourceConfig.jsonData, timeout: event.currentTarget.value },
+                      jsonData: { ...dataSourceConfig.jsonData, timeout: parseInt(event.currentTarget.value, 10) },
                     });
                   }}
                 />