[feat] add version template for the modify config option

[ChristofferNissen]

Add option to define a version based on a template, to dynamically use the chart version as part of the replace value

...
- name: chartname
  version: "1.2.3"
  repo:
    name: chartrepo
    url: https://raw.githubusercontent.com/"
  images:
    modify:
    - fromValuePath: image.repository
      to: "reg.io/repo/name"
    - fromValuePath: image.tag
      to: "v{.version}"
...

Becomes "reg.io/repo/name:v1.2.3"