init_fem dependencies on base_mesh

### Are there any linked Issues or Pull Requests?

_No response_

### Brief description

**init_fem** and other related subroutines have dependencies on the **geometry** and **topology** namelist parameters of **base_mesh**. This is problematic when having different meshes with different geometries and topologies, for example in the lfric2lfric application. The meshes can be interrogated instead to find the right geometry and topology. The subroutine **init_chi_transform** will not be modified, as it does not affect the results of lfric2lfric, and because it requires large changes in the API that would be better placed in a dedicated issue.

### Further details of the issue.

_No response_

Start by tracing init_fem and the other related subroutines that depend on base_mesh's geometry and topology namelist parameters, using the lfric2lfric application as the motivating case. Determine how the meshes can be interrogated for these values. Done means the relevant subroutines no longer rely on those base_mesh parameters, while init_chi_transform remains unchanged.

Written by the indexing model from the issue text.