'Show active file in explorer' should be 'Reveal active file in explorer'

[isidorn]

#5329

I believe 'Reveal active file in explorer' is a better name because it revealse the file and this name is more connected to the setting name explorer.autoReveal

I for instance needed some time to find the corresponding action in the command pallete because I was looking for reveal.

[bpasero]

I explicitly decided against that because it would make the other reveal action be #2 which imho has a lot more users.

[yomed]

FWIW it did take me a while to figure out that the command was workbench.files.action.showActiveFileInExplorer