Add quiet input to suppress info-level log output (#898)

## Summary

Adds a new `quiet` input (default: `false`) that suppresses `info`-level
log output when set to `true`. Only warnings and errors are shown.

Contributes to: #868

action-types.yml

@@ -56,6 +56,8 @@ inputs:
     type: boolean
   add-problem-matchers:
     type: boolean
+  quiet:
+    type: boolean
   resolution-strategy:
     type: enum
     allowed-values: