support updating doc mapping

[trinity-1686a]

this is a meta-ticket to group pull requests related to each others

• [ ] add doc mapping version to model (https://github.com/quickwit-oss/quickwit/pull/4928)
• [ ] don't merge incompatible splits (https://github.com/quickwit-oss/quickwit/pull/4928)
• [ ] add api to update the doc mapping ()
• [ ] plug doc mapping change to control-plan and restart indexing pipellines ()
• [x] fix fields disappearing if their type change (https://github.com/quickwit-oss/quickwit/pull/5076)
• [ ] fix getting errors about missing positions when updating what's recorded ()