feature: Auto-completion for kubernetes mid-string

[Delawen]

Continue #990 and #995

Now instead of auto-completing the whole value of the parameter, the string can contain several placeholders and other pieces of string that won't get removed by the auto-completion.

Screencast.from.2023-10-13.13-49-40.webm

[Delawen]

Not sure if this deserves a changelog or it can be included as part of the kubernetes context auto-completion lines in the changelog.

[apupier]

Not sure if this deserves a changelog or it can be included as part of the kubernetes context auto-completion lines in the changelog.

given that there was no release with it, i think we cna consider it as included in the other parts

[apupier]

• indentation: spaces are used in several places
• I think it is worthy to add test cases for:
  ** several placeholders
  ** }} being before a {{, so for the value, something like pgevent:host:999/database/channel?user=}}something{{a

[apupier]

Please rebase so that the PR is launched on Java 21.

(and it is a good habit to always rebase when providing new changes to ensure it is not diverging too much from main branch)