Fixed error logging. Added more logging of SIM info.

api/modem/internet/ic.go

@@ -103,7 +103,7 @@ func (c *conn) checkReqs() error {
 		return fmt.Errorf("AT+CPIN? request: %w", err)
 	}
 	if !resp.Check() {
-		return fmt.Errorf("SIM card is not inserted")
+		return fmt.Errorf("validate SIM: error response: %s", resp)
 	}
 	return nil
 }
@@ -115,7 +115,7 @@ func (c *conn) ConfigurePPP() error {
 		return fmt.Errorf("AT+CSPN? request: %w", err)
 	}
 	if !resp.Check() {
-		return fmt.Errorf("failed to check SIM provider")
+		return fmt.Errorf("get provider: error response: %s", resp)
 	}
 	strs := strings.Split(string(resp), "\"")
 	if len(strs) < 3 {