There is no specific point in the English Grammar Profile that suggests that “It was here that” is an example of introducing a cleft sentence for focus.
We know that inversion starts around the B1 level but this may be C2 Clefting similar to that with nouns. Looking at the low frequency in the iWeb corpus suggests this is quite advanced.
1 . IT WAS HERE THAT 3062
It was here that I met my master.
2 . IT WAS THERE THAT 2781
3 . IT IS HERE THAT 2576
4 . IT’S HERE THAT 667
5 . IT IS THERE THAT 527
6 . IT’S THERE THAT 180 *Note that we can omit ‘that’:
And it’s there I stayed until morning.
Compare the usual order:
I met my master here.
I stayed there.