feat(charts): Set new migration values and use bootloader image

[vnourdin]

What

since #8584, the server pod use some new variables, and we should use the bootloader image that manage db migrations.
This PR add everything needed in the helm chart.

How

• Create a Bootloader Pod
• add values for it
• add env variables
• update docs

[marcosmarxm]

thanks @vnourdin

[marcosmarxm]

@vnourdin can you solve the conflict so I can merge your contirbution?

[vnourdin]

@marcosmarxm it's done !

[alafanechere]

Thanks @vnourdin, ready to merge!

[alafanechere]

@vnourdin we have another PR which is also adding the env var for flyway job and config minimum versions. In his PR @mohamagdy exposed these env var as helm values. It's also a valid approach but I'm under the impression that it's fine to hardcode them in the ConfigMap (as you did) because they won't probably be changed by users, but I might be wrong. @davinchia what's your opinion on this? I'll merge but I'd be interested if you have a guideline about what should be hardcoded into ConfigMap and what should rather be exposed as values (only in the env var context).

[davinchia]

@alafanechere I don't have a strong opinion on whether the values should come from the configmap or be plain env vars. As long as it's easily configured whether the helm chart, I think it's ok!

[vnourdin]

I think it's always better to put everything that can change in values so that users only change one file.
If those version exists, I supposed they should sometimes change 🤷 I just did the simplest way 😅