Render content when the page is loaded

[sultan-duisenbay]

Getting rid of the buttons to call API and instead do that during the loading/rendering stage - similar to how it's done in the current Testgrid UI.

Notable changes

• Removed call API button from index. Removed the input and button from dashboard summary page.
• Index and dashboard summary content is rendered when the page is loaded.
• Clicking on any dashboard will navigate directly to the dashboard summary page of that dashboard
• Added test for <dashboard-summary> component

[google-oss-prow[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: chases2, sultan-duisenbay

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