Maintain mode between files

Is your feature request related to a problem? Please describe.
It's annoying when I switch files and the mode isn't persisted between them. Imagine I have multiple files open in the editor, and I'm currently in Normal mode. If I tab over to another file that was previously in Insert mode, I will go to insert mode. If I haven't edited that file in a while, I might not remember that I was in Insert mode. So essentially every file switch, I have to go into Normal mode or check my current mode, which just feels unnecessary.

Describe the solution you'd like
A boolean setting option, something like vim.maintainModeBetweenFiles: true | false, where the user can set their preference for Vim keeping the mode between files.

Describe alternatives you've considered
vim.startInInsertMode is a little closer, but there are no options for starting in Normal Mode.

The issue names no files, tests, or entry points; start by locating how VSCodeVim handles file switches and tracks the current mode. Done means a configurable maintain-mode setting preserves the user's preferred mode between files while allowing the existing behavior to remain available.