Rename "model adaptivity" because it conflicts with "adaptivity"

[IshaanDesai]

@MakisH recently pointed out that the adaptivity feature name is problematic because it suggests that model adaptivity is part of it. This, however, is not the case. Adaptivity refers to adaptive computation of micro-scale problems based on a similarity criterion, while model adaptivity refers to adaptive computation of micro-scale problems based on on-the-fly switching of micro-scale models. Therefore, the name adaptivity needs to change to reflect what it actually is. One suggestion is similarity adaptivity.

[MakisH]

From our discussion, I understood that "adaptivity" is rather established, but "model adaptivity" is not. Renaming "model adaptivity" to "(adaptive|dynamic) model selection" or similar would also solve this.

[IshaanDesai]

From our discussion, I understood that "adaptivity" is rather established, but "model adaptivity" is not. Renaming "model adaptivity" to "(adaptive|dynamic) model selection" or similar would also solve this.

While it is true that "adaptivity" has been used in literature before, I checked again, and it is not established with respect to the computation based on a similarity criterion. So we could change the term. But changing "model adaptivity" is also an option.