Bump blockdiag and *diag dependencies to 3.0.0

[nejch]

Related to blockdiag/blockdiag#147.

Replaces #1016, #1015, #1014, #1013 because they require funcparserlib 1.0.0a0 to work (as discussed in blockdiag PRs).

[nejch]

@Mogztter I also had to change a few fixtures, might be related to some additional margins in 3.0.0 though I haven't explored in detail (see https://github.com/blockdiag/seqdiag/blob/master/CHANGES.rst#300-2021-12-06).

[ggrossetie]

Replaces #1016, #1015, #1014, #1013 because they require funcparserlib 1.0.0a0 to work (as discussed in blockdiag PRs).

@nejch Woot woot, thanks! 🎉

I also had to change a few fixtures, might be related to some additional margins in 3.0.0 though I haven't explored in detail (see blockdiag/seqdiag@master/CHANGES.rst#300-2021-12-06).

I think it's fine, changes seem relatively small and harmless.