Move/rename linear algebra files

[pcarruscag]

Proposed Changes

Quick followup on PR #700 to rename the linear algebra files according to class and move them to a dedicated directory.
Trailing spaces have been stripped and EOL's made consistent.
This does not introduce any code changes.

Related Work

#583
#700

PR Checklist

• I am submitting my contribution to the develop branch.
• My contribution generates no new compiler warnings (try with the '-Wall -Wextra -Wno-unused-parameter -Wno-empty-body' compiler flags).
• My contribution is commented and consistent with SU2 style.
• I have added a test case that demonstrates my contribution, if necessary.

[WallyMaier]

Thanks for doing this! This looks great, and makes the code, in my opinion, easier to understand. I appreciate the cleaning of the white space as well.

[pcarruscag]

Thanks @WallyMaier , now that there is no single tab in sight it should look better.