fix: git credential scoping issue for `packages`

Description

Fixes logic for generating git credential secrets for packages. There is a scoping issue in the gitcredential secret template that currently breaks the BigBang helm chart when attempting to supply .git.credentials. See #1712 (closed) for more details

This also fixes another bug where the secretRef in packages git repo's did not match the secret name generated for the package

Tests

Reproducing error found in issue

Using code found on master branch and using default values from chart along with the following packages-values:

packages:
  podinfo:
    git:
      repo: https://github.com/stefanprodan/podinfo.git
      tag: 6.3.4
      path: charts/podinfo
    flux:
      timeout: 5m
    postRenderers: []
    dependsOn:
      - name: monitoring
        namespace: bigbang
    values:
      replicaCount: 3

git:
  credentials:
    password: somepass
    username: someuser
registryCredentials:
  password: somepass
  registry: someregistry
  username: someuser

I receive the following error as expected:

Error: template: bigbang/templates/secrets/gitcredential.yaml:13:8: executing "bigbang/templates/secrets/gitcredential.yaml" at <include "commonLabels" .>: error calling include: template: bigbang/templates/_helpers.tpl:86:39: executing "commonLabels" at <.Release.Name>: can't evaluate field Release in type string

Negative Test Case (Without supplying .git.credentials)

Using default values from chart along with the following packages-values:

packages:
  podinfo:
    git:
      repo: https://github.com/stefanprodan/podinfo.git
      tag: 6.3.4
      path: charts/podinfo
    flux:
      timeout: 5m
    postRenderers: []
    dependsOn:
      - name: monitoring
        namespace: bigbang
    values:
      replicaCount: 3

registryCredentials:
  password: somepass
  registry: someregistry
  username: someuser

Successfully generates the following git repo (did not generate secret as expected):

---
# Source: bigbang/templates/package/gitrepository.yaml
apiVersion: source.toolkit.fluxcd.io/v1
kind: GitRepository
metadata:
  name: podinfo
  namespace: podinfo
  labels:
    app.kubernetes.io/name: podinfo
    app.kubernetes.io/instance: bb
    app.kubernetes.io/version: 2.10.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/part-of: "bigbang"
    helm.sh/chart: bigbang-2.10.0
spec:
  interval: 2m
  url: https://github.com/stefanprodan/podinfo.git
  ref:
    tag: 6.3.4

Positive Test Case

Using default values from chart along with the following packages-values:

packages:
  podinfo:
    git:
      repo: https://github.com/stefanprodan/podinfo.git
      tag: 6.3.4
      path: charts/podinfo
    flux:
      timeout: 5m
    postRenderers: []
    dependsOn:
      - name: monitoring
        namespace: bigbang
    values:
      replicaCount: 3

git:
  credentials:
    password: somepass
    username: someuser
registryCredentials:
  password: somepass
  registry: someregistry
  username: someuser

Successfully generates the following git repo with secretref and the associated secret:

---
# Source: bigbang/templates/package/gitrepository.yaml
apiVersion: source.toolkit.fluxcd.io/v1
kind: GitRepository
metadata:
  name: podinfo
  namespace: podinfo
  labels:
    app.kubernetes.io/name: podinfo
    app.kubernetes.io/instance: bb
    app.kubernetes.io/version: 2.10.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/part-of: "bigbang"
    helm.sh/chart: bigbang-2.10.0
spec:
  interval: 2m
  url: https://github.com/stefanprodan/podinfo.git
  ref:
    tag: 6.3.4
  secretRef:
    name: bb-git-credentials
---
# Source: bigbang/templates/secrets/gitcredential.yaml
apiVersion: v1
kind: Secret
metadata:
  name: bb-git-credentials
  namespace: podinfo
  labels:
    app.kubernetes.io/name: bb-git-credentials
    app.kubernetes.io/instance: bb
    app.kubernetes.io/version: 2.10.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/part-of: "bigbang"
    helm.sh/chart: bigbang-2.10.0
type: Opaque
data:
  username: c29tZXVzZXI=
  password: c29tZXBhc3M=

Package Changes

None

Package MR

None

For Issue

Closes #1712 (closed)