feat(charts/dex): add extraObjects

[TheRealNoob]

Overview

What this PR does / why we need it

Closes #23 #130 https://github.com/dexidp/dex/issues/3227

add extraObjects object, allowing people to define their own (set of) custom manifests

Special notes for your reviewer

Checklist

• [x ] Change log updated in Chart.yaml (see the contributing guide for details)
• [ x] Chart version bumped in Chart.yaml (see the contributing guide for details)
• [ x] Documentation regenerated by running make docs

[TheRealNoob]

@nabokihms Could I bother you for a review please? There is another PR https://github.com/dexidp/helm-charts/pull/143 open aiming to do the same thing - one should be merged the other closed.

[skhtor]

I've added this functionality to a bunch of our charts in my organisation. I'm +1 in favour of allowing extraObjects to be inputted as a dict, as it allows for merging across multiple values files

[cardoe]

@TheRealNoob You'll need to add a sign off to acknowledge the DCO. git commit --amend --signoff and push again.

[TheRealNoob]

@cardoe ready for re-review

[TheRealNoob]

bumped the chart patch version when i should have bumped the minor version. fixed.