Revise inline fragments normalization

[gohabereg]

Currently inline fragments are merged in case two neighbouring fragments:

1. are from the same tool
2. the second fragment starts at index where the first one ends

How it should work ideally:

1. Two fragments in the fragments array are from the same tool
2. The second fragment starts at index where the first one ends

Naive solution would be O(n^2), we should think of more efficient solution