Report system legacy code cleanup

- Rename two functions that work with guids instead of names (legacy)
- Don't sort the a list of guids. This doesn't add value and slows down the report loading code
- Add/improve some comments
- Reorder record accessors for the report-template record

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23067 57a11ea4-9604-0410-9ed3-97b8803252fd
Report system: regroup legacy functions

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23068 57a11ea4-9604-0410-9ed3-97b8803252fd
Report system - emit warning when trying to restore named-based saved reports

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23069 57a11ea4-9604-0410-9ed3-97b8803252fd