vi mode cursor position isn't vi-like

[crides]

2 main issues I can observe:

1. Escape doesn't move the cursor back.

   For example, interleaving i and escape moves the cursor back one by one (in both vim and zsh vi mode)

2. Moving to the last character puts the cursor after the last character, not on top of it. Note: $ is not the only way to achieve this

   For example, having asdf and the cursor at the front (position 0), and pressing any one of w, W, E, e, $ in normal mode, or just pressing right arrows should put the cursor on top of f.