apisix-ingress-controller Helm Chart features & fixes

We are currently working on implementation of `apisix` into our EKS cluster. And it seems that Helm Chart is missing some of the features or has some bugs. Instead of opening many issues for you to resolve, I have tried to submit PRs with fixes/improvements.

We are currently installing `apisix-ingress-controller` Helm Chart using Flux CD, so many things can be workaround using `kustomize` `postRenderer`, but having these directly in Helm Chart would make things easier, see:

```
---
apiVersion: helm.toolkit.fluxcd.io/v2beta1
kind: HelmRelease
metadata:
name: ingress-apisix
namespace: ingress-apisix
spec:
chart:
spec:
chart: [REDACTED]/apisix/apisix-ingress-controller
reconcileStrategy: ChartVersion
sourceRef:
kind: HelmRepository
name: [REDACTED]
namespace: flux-system
version: 0.13.0
interval: 1h
postRenderers:
- kustomize:
patches:
- patch: |
- op: add
path: /metadata/annotations/reloader.stakater.com~1auto
value: "true"
- op: add
path: /spec/template/spec/containers/1/resources
value: {"limits": {"cpu": "1", "memory": "1Gi"}, "requests": {"cpu": "100m", "memory": "128Mi"}}
- op: add
path: /spec/template/spec/containers/1/securityContext
value: {"capabilities": {"add": ["NET_BIND_SERVICE"]}}
target:
kind: Deployment
name: apisix-ingress-controller
version: v1
values:
[...]
```

For this matter, I am submitting a overview of PRs for you to review and potentially merge (I don't mind further improving PRs if needed and if review is provided):

- Support for annotations in Deployment object (needed for reloader to work): https://github.com/apache/apisix-helm-chart/pull/697
- Support for PodDisruptionBudget policy: https://github.com/apache/apisix-helm-chart/pull/695
- Support for configuring resources of gateway container (kind of critical PR): https://github.com/apache/apisix-helm-chart/pull/694
- Support for configuring securityContext for gateway container: https://github.com/apache/apisix-helm-chart/pull/702
- Fix of TLS (SSL) configuration of gateway container: https://github.com/apache/apisix-helm-chart/pull/703

There is one more thing missing - support for enabling/disabling apisix plugins in the configMap (e.g. zipkin is enabled by default, but opentelemetry is not, and we would like to have it vice-versa).

EDIT:
Additional PRs:
- https://github.com/apache/apisix-helm-chart/pull/706
- https://github.com/apache/apisix-helm-chart/pull/712