Name `transform` is confusing

I always trip when I see a variable or function accessor `transform` in ACTS because it does not tell me what it transforms. It could be either `local->global` or `global->local` and it happened to me couple of times that I ended up on the wrong side. I believe this is the case for others too looking at https://github.com/acts-project/acts/pull/4466.

**Potential alternatives**
- ~`localToGlobal` / `globalToLocal`~
- ~`local2global` / `global2local`~
- `localToGlobalTransform` / `globalToLocalTransform`
- chosen over `localToGlobal` because this name already exists in `Acts::Surface` and does something else

**Progress towards improving this**
- [x] https://github.com/acts-project/acts/pull/4954
- [x] https://github.com/acts-project/acts/pull/4958