Find templates without symlinks

[scymtym]

Is your feature request related to a problem? Please describe.

Adding and maintaining templates which can be shared between modes is made more complicated than necessary by the fact that symbolic links have be created and maintained for each new shared template.

Describe the solution you'd like

It would be better if the generator tried the possible template paths until it finds the file. E.g. when looking for cmake-base in toolkit mode the generator should try templates/toolkit/cmake-base.template, then templates/_common/cmake-base.template.