(io): read tfp TF from directory with ::uiTF::SMultipleTF

Description

Before, ::uiTF::SMultipleTF loaded the pool from paths, but read only .json TF. Now, '.tfp` files are also read.

Closes #604 (closed)

How to test it?

• Create tfp TF from OgreViewer.
• Add them in sight\modules\ui\uiTF\rc\tf.
• Now if you launch OgreViewer, they should be in the TF editor.