Allow web deployment value to be configured through values

[frankh]

Description

Allow deployment kind+strategy to be customised with values so that we can switch to argo rollouts

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How has this been tested?

existing tests should pass with no changes
will add tests to verify once a PoC has been deployed in dev

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works