Align rallly chart with repo conventions (batch 3)

- Rename the Deployment (and its labels/selector/pod template/container)
  to {{ .Release.Name }}-{{ .Chart.Name }}-deployment per the naming
  scheme; the Service selector follows.
- Move the hardcoded pod/container security contexts into values
  (rallly.securityContext.pod / .container), defaults unchanged; the
  bogus null entry under capabilities.add becomes an empty list.
- Ingress standard: ingress.className value (default nginx) and
  ingress.annotations merged with the cert-manager annotation;
  domain/clusterIssuer stay required, TLS secret name already conformed.
- Add the tpl-rendered rallly.env value (value/secretKeyRef/
  configMapKeyRef forms), appended to the built-in env.
- Major bump 3.1.2+up4.12.3 -> 4.0.0+up4.12.3 (deployment rename
  replaces the Deployment on upgrade: selector is immutable).

rallly/templates/rallly.ingress.yaml

@@ -3,9 +3,12 @@ kind: Ingress
 metadata:
   name: {{ .Release.Name }}-{{ .Chart.Name }}-ingress
   annotations:
-    cert-manager.io/cluster-issuer: {{ required "A Cluster-Issuer must be provided" .Values.ingress.clusterIssuer}}
+    cert-manager.io/cluster-issuer: {{ required "A Cluster-Issuer must be provided" .Values.ingress.clusterIssuer }}
+    {{- with .Values.ingress.annotations }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
 spec:
-  ingressClassName: nginx
+  ingressClassName: {{ .Values.ingress.className }}
   rules:
     - host: {{ required "A Domain/Host must be provided" .Values.ingress.domain }}
       http: