Remove content of some commands from the natural flow (footnotes)

[tobiasdiez]

Is your feature request related to a problem? Please describe.
Some commands don't add text at exactly this point, but display their arguments as footnotes or in the margin (e.g. \footnote or \todo). This is currently not supported by ltex. For example
Test is a fibration\footnote{Fibration in the sense of Serre.}
reports a "repeated word warning" for fibration.

Describe the solution you'd like
Remove these sentences from the normal text and check them separately.

Describe alternatives you've considered
Couldn't come up with good alternatives. One could convert footnote to a dummy text, but this also destroys the original sentence.

[tobiasdiez]

That was quick. Thanks a lot!

[valentjn]

@tobiasdiez No worries. Fix released in 5.0.0.