Tweaks to the contextmenu

[alexdima]

@jrieken

• add Go to Implementation
• add Go to References
• remove "Peek" commands
• move Find All References to its own group

Before	After

[jrieken]

This left to be done:

• extends the editor.gotoLocation.multiple-setting (Polish existing code navigation gestures #83752) so that it can be configured per navigation feature
• change the group in the references-view-extensions (mock'ed in the screen shots)
• (optionally) remove the peek command as they are subsumed by the setting above

[egamma]

A spelling nit... in the proposal it is:

• go to definition -> singular, since the common case is that there is a single definition
• go to references -> plural, since the common case is that there are many references

Assuming that multiple implementations is the common case, then it should be 'go to implementations' , or 'go to implementation(s)'

[jrieken]

This is how it now looks. Note that in some language there might also be an additional "Go to Declaration" entry, e.g for C/CPP. There is now also a setting for each feature, e.g. editor.gotoLocation.multipleImplemenations which defines how it should behave in case multiple exist