TUN-10389: Implement main run method

This introduces  the main precheck logic. This will follow concurrency model, timeout handling, and retry logic established in the SPEC. We will follow the decision flow in the [connectivity pre-checks SPEC](https://wiki.cfdata.org/spaces/TUN/pages/1374967685/Connectivity+Pre-checks+for+cloudflared). You can find an attached image of what the decision flow should look like.

![image.png](/uploads/fa71215adc2da509f6cbbb74532e3d95/image.png){width=900 height=235}

prechecks/types.go

@@ -57,22 +57,20 @@ type CheckResult struct {
 	Type ProbeType
 
 	// Component is the human-readable probe category shown in the table header
-	// column, e.g. "DNS Resolution", "QUIC Connectivity".
+	// column
 	Component string
 
-	// Target is the address or resource that was probed, e.g.
-	// "region1.v2.argotunnel.com" or "Port 7844 (QUIC)".
+	// Target is the address or resource that was probed
 	Target string
 
 	// ProbeStatus is the outcome of the probe.
 	ProbeStatus Status
 
-	// Details is a short description of the result shown in the table, e.g.
-	// "Resolved successfully" or "Handshake failed".
+	// Details is a short description of the result shown in the table
 	Details string
 
 	// Action is non-empty when ProbeStatus is Fail and contains a human-readable
-	// remediation instruction, e.g. "Allow outbound QUIC on port 7844."
+	// remediation instruction
 	Action string
 }