fix(eventhandler): add newEventHandler() as tjcontroller.Options

[haarchri]

Description of your changes

fix(eventhandler): add newEventHandler() as tjcontroller.Options

fix the following issue with new upjet version:

2023-08-03T14:57:52+02:00       INFO    Starting workers        {"controller": "managed/escalation.pagerduty.crossplane.io/v1alpha1, kind=policy", "worker count": 10}
E0803 14:57:57.720685   68417 runtime.go:79] Observed a panic: "invalid memory address or nil pointer dereference" (runtime error: invalid memory address or nil pointer dereference)
goroutine 900 [running]:
k8s.io/apimachinery/pkg/util/runtime.logPanic({0x10423eca0?, 0x1053fefe0})
        k8s.io/apimachinery@v0.27.3/pkg/util/runtime/runtime.go:75 +0x7c
k8s.io/apimachinery/pkg/util/runtime.HandleCrash({0x0, 0x0, 0x1044cf540?})
        k8s.io/apimachinery@v0.27.3/pkg/util/runtime/runtime.go:49 +0x78
panic({0x10423eca0, 0x1053fefe0})
        runtime/panic.go:884 +0x204
github.com/upbound/upjet/pkg/controller/handler.(*EventHandler).setQueue(0x0, {0x1044f4ac0?, 0x1400004c200})
        github.com/upbound/upjet@v0.10.0-rc.0.0.20230802121849-caa74d2aebf2/pkg/controller/handler/eventhandler.go:89 +0x30
github.com/upbound/upjet/pkg/controller/handler.(*EventHandler).Create(0x0, {0x1044eb9c0, 0x14000c287c0}, {{0x1044feb00?, 0x14000c3a000?}}, {0x1044f4ac0, 0x1400004c200})
        github.com/upbound/upjet@v0.10.0-rc.0.0.20230802121849-caa74d2aebf2/pkg/controller/handler/eventhandler.go:97 +0x48
sigs.k8s.io/controller-runtime/pkg/internal/source.(*EventHandler).OnAdd(0x14000466f00, {0x1044b26e0?, 0x14000c3a000})
        sigs.k8s.io/controller-runtime@v0.15.0/pkg/internal/source/event_handler.go:88 +0x1e4
k8s.io/client-go/tools/cache.ResourceEventHandlerFuncs.OnAdd(...)
        k8s.io/client-go@v0.27.3/tools/cache/controller.go:243
k8s.io/client-go/tools/cache.(*processorListener).run.func1()
        k8s.io/client-go@v0.27.3/tools/cache/shared_informer.go:973 +0x164
k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0x0?)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:226 +0x40
k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0x14000ee0f28?, {0x1044d3180, 0x14000cc1f50}, 0x1, 0x14000666f60)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:227 +0x90
k8s.io/apimachinery/pkg/util/wait.JitterUntil(0x0?, 0x3b9aca00, 0x0, 0x0?, 0x0?)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:204 +0x80
k8s.io/apimachinery/pkg/util/wait.Until(...)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:161
k8s.io/client-go/tools/cache.(*processorListener).run(0x14000c70b40?)
        k8s.io/client-go@v0.27.3/tools/cache/shared_informer.go:967 +0x68
k8s.io/apimachinery/pkg/util/wait.(*Group).Start.func1()
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/wait.go:72 +0x58
created by k8s.io/apimachinery/pkg/util/wait.(*Group).Start
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/wait.go:70 +0x84
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x28 pc=0x1037508c0]

goroutine 900 [running]:
k8s.io/apimachinery/pkg/util/runtime.HandleCrash({0x0, 0x0, 0x1044cf540?})
        k8s.io/apimachinery@v0.27.3/pkg/util/runtime/runtime.go:56 +0xe4
panic({0x10423eca0, 0x1053fefe0})
        runtime/panic.go:884 +0x204
github.com/upbound/upjet/pkg/controller/handler.(*EventHandler).setQueue(0x0, {0x1044f4ac0?, 0x1400004c200})
        github.com/upbound/upjet@v0.10.0-rc.0.0.20230802121849-caa74d2aebf2/pkg/controller/handler/eventhandler.go:89 +0x30
github.com/upbound/upjet/pkg/controller/handler.(*EventHandler).Create(0x0, {0x1044eb9c0, 0x14000c287c0}, {{0x1044feb00?, 0x14000c3a000?}}, {0x1044f4ac0, 0x1400004c200})
        github.com/upbound/upjet@v0.10.0-rc.0.0.20230802121849-caa74d2aebf2/pkg/controller/handler/eventhandler.go:97 +0x48
sigs.k8s.io/controller-runtime/pkg/internal/source.(*EventHandler).OnAdd(0x14000466f00, {0x1044b26e0?, 0x14000c3a000})
        sigs.k8s.io/controller-runtime@v0.15.0/pkg/internal/source/event_handler.go:88 +0x1e4
k8s.io/client-go/tools/cache.ResourceEventHandlerFuncs.OnAdd(...)
        k8s.io/client-go@v0.27.3/tools/cache/controller.go:243
k8s.io/client-go/tools/cache.(*processorListener).run.func1()
        k8s.io/client-go@v0.27.3/tools/cache/shared_informer.go:973 +0x164
k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0x0?)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:226 +0x40
k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0x14000ee0f28?, {0x1044d3180, 0x14000cc1f50}, 0x1, 0x14000666f60)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:227 +0x90
k8s.io/apimachinery/pkg/util/wait.JitterUntil(0x0?, 0x3b9aca00, 0x0, 0x0?, 0x0?)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:204 +0x80
k8s.io/apimachinery/pkg/util/wait.Until(...)
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/backoff.go:161
k8s.io/client-go/tools/cache.(*processorListener).run(0x14000c70b40?)
        k8s.io/client-go@v0.27.3/tools/cache/shared_informer.go:967 +0x68
k8s.io/apimachinery/pkg/util/wait.(*Group).Start.func1()
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/wait.go:72 +0x58
created by k8s.io/apimachinery/pkg/util/wait.(*Group).Start
        k8s.io/apimachinery@v0.27.3/pkg/util/wait/wait.go:70 +0x84
make: *** [run] Error 2

Fixes #

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

[github-actions]

Successfully created backport PR #23 for release-0.5.