feat: add hold file for chart upgrade

[rgee0]

Description

Adds a feature to the chart upgrade command such that images within the target file can be ignored during the upgrade if they are detailed in a hold file. To be considered the file should follow the name of the yaml file passed by -f suffixed with .hold, e.g. upgrading docker-compose.yaml would look for a docker-compose.yaml.hold.

The hold file format is:

component1.image
db.image
...
nats.image

Motivation and Context

• I have raised an issue to propose this change, which has been given a label of design/approved by a maintainer (required)
  Closes Upgrading container image tags - hold feature #1132

How Has This Been Tested?

TBC

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Documentation

• I have updated the list of tools in README.md if (required) with ./arkade get --format markdown
• I have updated the list of apps in README.md if (required) with ./arkade install --help

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s

• I have tested this on arm, or have added code to prevent deployment

[rgee0]

filtered will be non-zero as we return earlier if len==0