Add ability to map <TAB> and <C-I> separately like XTerm or iTerm2 have done

Is your feature request about something that is currently impossible or hard to do? Please describe the problem.
Currently we can't remap for example <TAB> and <C-I> separately, they both always do the same thing.

Describe the solution you'd like
Would be nice if these, and other control keys (<CR> and <C-M>, <BS> and <C-H> etc.), could be mapped separately.

Additional context
<TAB> and <C-I> can already be mapped separately in a Vim 8.2 running XTerm using modifyOtherKeys https://invisible-island.net/xterm/modified-keys.html or in iTerm2 when 'Control sequences can enable modifyOtherKeys mode' has been enabled from Preferences -> Profiles -> Keys.

One can easily test if the keys get registered separately with:

nnoremap <C-I> :echom "Ctrl-I was pressed"<CR>
nnoremap <TAB> :echom "Tab was pressed"<CR>

まず、issue にある 2 つの nnoremap コマンドでマッピングの動作を再現し、次に XTerm modifyOtherKeys のドキュメントを読んで、MacVim のキーボード入力処理と比較します。 と 、および аналогous な control-key ペアで別々のマッピングを発動でき、例のコマンドが異なるメッセージを報告できるようになれば作業は完了です。