fix: remove unnecessary qos data record form pcc ruls

[Alonza0314]

This PR addresses issue #627.

Upon tracing, I found that the default PCC rule created by the PCF contains nil QoS data, which is transformed into a new QoS rule with QFI=2. This is unnecessary and redundant. However, there is two pieces of data required by the SMF: the default charging data. Therefore, it is not necessary to store this default PCC rule in smContext.PCCRules after extracting the charging data.

In the original code, if a customized flow rule is set via the web console, two additional QoS flows are added to smContext.AdditionalQosFlows. These include one default PCC rule and the customized rule based on the decision made by the PCF. With this update, I discard the default PCC rule and retain only the customized rules. This ensures that the number of QoSDescriptions and the items in QosFlowSetupRequestList in the NAS packet are accurate.

Changes Made:

• If a PCC rule does not contain a QoSID (indicating no QoS data), it will not allocate a QFI to it.
• Only PCC rules with a QoSID (indicating QoS data) are stored and appended to smContext.AdditionalQosFlows as QoS rules.

I have tested that with this modification, traffic and charging remain functional as before.

[ianchen0119]

@Alonza0314
Plz apply the patch into next branch.

Thanks.