fix: wrong Pod's UID and emtpy Pod's name in log of webhook.go

[Shouren]

What type of PR is this?
/kind bug

What this PR does / why we need it:
This PR updates the Handle() func in pkg/scheduler/webhook.go. The previous implementation using req.UID and req.Name when logging. However, according to the doc of AdmissionRequest as below:

// UID is an identifier for the individual request/response. It allows us to distinguish instances of requests which are
// otherwise identical (parallel requests, requests when earlier requests did not modify etc)
// The UID is meant to track the round trip (request/response) between the KAS and the WebHook, not the user request.
// It is suitable for correlating log entries between the webhook and apiserver, for either auditing or debugging.
UID types.UID json:"uid" protobuf:"bytes,1,opt,name=uid"

req.UID is not equal to pod.UID, as shown in the following screenshot.

And the req.Name might be empty according the above doc:

// Name is the name of the object as presented in the request. On a CREATE operation, the client may omit name and
// rely on the server to generate the name. If that is the case, this field will contain an empty string.
// +optional
Name string json:"name,omitempty" protobuf:"bytes,5,opt,name=name"

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:
@archlitchi

Does this PR introduce a user-facing change?:

[hami-robott]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Shouren
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[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pkg/scheduler/webhook.go	50.00%	3 Missing ⚠️

Flag	Coverage Δ
unittests	61.08% <50.00%> (+0.06%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
pkg/scheduler/webhook.go	56.00% <50.00%> (ø)

... and 1 file with indirect coverage changes

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