[C++] Refactor bundled dependencies from ExternalProject to FetchContent

### Describe the enhancement requested

This is a tracking issue for refactoring the bundled part of the Arrow C++ build from using CMake ExternalProject to FetchContent. Please comment on this issue if you have anything to add to this post or want to help clarify anything.

Related issues:

- [x] The build system is currently being upgraded from 3.16 to 3.25: https://github.com/apache/arrow/pull/44989

Related discussions:

- [Zulip: Dev > CMake minimum required version (2024/11/12)](https://ursalabs.zulipchat.com/#narrow/channel/180245-dev/topic/CMake.20minimum.20required.20version/)

Tasks that depend on FetchContent:

- [ ] https://github.com/apache/arrow/issues/45297
- Once we use FetchContent, the patch described in this issue can be removed from our vcpkg port
- [x] https://github.com/apache/arrow/issues/45195
- [x] https://github.com/apache/arrow/issues/45063
- [x] https://github.com/apache/arrow/issues/48074
- [x] https://github.com/apache/arrow/issues/48091
- [x] https://github.com/apache/arrow/issues/48178
- [x] https://github.com/apache/arrow/issues/48181
- [x] https://github.com/apache/arrow/issues/48248
- [x] https://github.com/apache/arrow/issues/48315
- [x] https://github.com/apache/arrow/issues/48316
- [x] https://github.com/apache/arrow/issues/48317
- [x] https://github.com/apache/arrow/issues/48555

cc @kou @assignUser @raulcd

### Component(s)

C++