Default standard_1020 montage contains realistic, not template positions

Describe the bug

On the current master (i.e., after #7066) frontal EEG channels are drawn outside of the head in topoplots.

Steps to reproduce

The simplest variant is probably mne.viz.plot_montage(mne.channels.make_standard_montage('standard_1020')) Naturally it also occurs in plot_topomap and is particularly suboptimal for outline='head' and extrapolate='head'.

Expected results

I would expect the head circumference to intersect the positions of the outer AF, F, FT, … PO, O electrodes. This would match previous behavior and common plots (e.g., the 10-05 paper http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.116.7379&rep=rep1&type=pdf or https://github.com/sappelhoff/eeg_positions).

Actual results

Hence, the head seems to be shifted vertically (T9 and T10 are also not vertically centered with respect to the ears).

Additionally, the comment in the extrapolation snippet https://mne.tools/dev/auto_examples/visualization/plot_evoked_topomap.html suggests that changing the sphere diameter has an influence, but it didn’t result in any changes for me.

[hoechenberger]

Wow, that’s… that’s horrible!!?

[drammock]

if we do so we should probably just get rid of standard_1020 altogether and have standard_1020_sphere and standard_1020_realistic as the new options to force people to be explicit about their choice.

👍 for this suggestion. It’s disruptive, but IMO that’s better than silently having old code make plots look different enough to cause people to get annoyed.