Follow-up from "Add ability to set camera projection offset from lua (#9030)" should RenderTargetMap be keyed by string_view

AnyOldName3
2026-03-27T18:05:18Z

The following discussion from !5228 should be addressed:

- [ ] @uramer started a [discussion](https://gitlab.com/OpenMW/openmw/-/merge_requests/5228#note_3198508313): (+10 comments)

> Was this change just for clarity, or is there some functional change happening here?

To avoid this warning (treated as error):

```
error: object whose reference is captured by 'technique->getRenderTargetsMap()' will be destroyed at the end of the full-expression [-Werror,-Wdangling-capture]
649 | auto& renderTarget = technique->getRenderTargetsMap()[pass->getTarget()];
| ^~~~~~~~~~~~~~~~~
1 error generated.
```
we bound the `std::string` returned by `getTarget` to a variable.

`getTarget` should probably return a string view instead of a copy of the string.

There's also an open question of whether it's safe for `RenderTargetMap` to be keyed by `std::string_view` as then something external has to keep the viewed strings alive while the map's alive instead of letting the map own its own keys.