RET should invoke lem-core::color-theme-selector-select in vi-mode's normal mode too

[g-gundam]

Steps to Reproduce

1. M-x vi-mode
2. M-x list-color-themes
3. Place cursor over desired theme.
4. Hit RET

Expectation

The theme is selected.

Result

Nothing happens.

HOWEVER!

5. Go into insert mode by hitting i.
6. Place cursor over desired theme.
7. Hit RET

Result

The theme is selected, but you have to be in insert mode.

I feel like RET should activate a theme in normal mode too.

[g-gundam]

I noticed a similar issue in M-x filer. In normal mode, RET doesn't do anything. However, if I switch to insert mode while in filer, RET opens the file at point.

I shouldn't have to be in insert mode to use filer.