vim-patch:8.1.1927: code for dealing with script files is spread out

Problem:    Code for dealing with script files is spread out.
Solution:   Move the code to scriptfile.c. (Yegappan Lakshmanan, closes vim/vim#4861)
https://github.com/vim/vim/commit/307c5a5bb77c3728dfab06c30e9f786309c63f74

Problem:    Profiling functionality is spread out.
Solution:   Put profiling functionality in profiling.c. (Yegappan Lakshmanan,
            closes vim/vim#4666)
https://github.com/vim/vim/commit/fa55cfc69d2b14761e2a8bd85bc1e0d82df770aa

Move proftime_T to types.h for now to avoid recursive #include.

Vim moved them there in patch 8.1.1943.

Problem:    The eval.c file is too big.
Solution:   Move code related to variables to evalvars.c. (Yegappan
            Lakshmanan, closes vim/vim#4868)
https://github.com/vim/vim/commit/0522ba0359c96a8c2a4fc8fca0d3b58e49dda759

Name the new file eval/vars.c instead.

This marks the following Vim patches as ported:

vim-patch:8.1.1785: map functionality mixed with character input

Problem:    Map functionality mixed with character input.
Solution:   Move the map functionality to a separate file. (Yegappan
            Lakshmanan, closes vim/vim#4740)  Graduate the +localmap feature.
https://github.com/vim/vim/commit/b66bab381c8ba71fd6e92327d1d34c6f8a65f2a7

vim-patch:8.2.3643: header for source file is outdated

Problem:    Header for source file is outdated.
Solution:   Make the header more accurate. (closes vim/vim#9186)
https://github.com/vim/vim/commit/a3f83feb63eae5464a620ae793c002eb45f7a838

Also cherry-pick a change for <unique> mappings from patch 8.2.0807.
Rename map_clear_mode() to do_mapclear().

    In scripts/vim-patch.sh line 335:
      printf '
             ^-- SC2183 (warning): This format string has 4 variables, but is passed 3 arguments.

    In scripts/vim-patch.sh line 597:
      list_missing_vimpatches 1 "$@" | while read -r vim_commit; do
                                                     ^--------^ SC2030 (info): Modification of vim_commit is local (to subshell caused by pipeline)

    In scripts/vim-patch.sh line 626:
      done < <(git -C "${VIM_SOURCE_DIR}" diff-tree --no-commit-id --name-only -r "${vim_commit}" -- . ':!src/version.c')
                                                                                   ^-----------^ SC2031 (info): vim_commit was modified in a subshell. That change might be lost.

    For more information:
      https://www.shellcheck.net/wiki/SC2183 -- This format string has 4 variable...
      https://www.shellcheck.net/wiki/SC2030 -- Modification of vim_commit is loc...
      https://www.shellcheck.net/wiki/SC2031 -- vim_commit was modified in a subs...

https://github.com/vim/vim/commit/388a5d4f20b4b64341d1604aa238cab85827b892
https://github.com/vim/vim/commit/4466ad6baa22485abb1147aca3340cced4778a66
https://github.com/vim/vim/commit/6aa57295cfbe8f21c15f0671e45fd53cf990d404

Rename terminal.txt to nvim_terminal_emulator.txt in vim-patch.sh.

Most code in keymap.h is for keycode definitions, while most code in
keymap.c is for the parsing and conversion of keycodes.

The name "keymap" may also make people think these two files are for
mappings, while in fact keycodes are used even when no mappings are
involved, so "keycodes" should be a better file name than "keymap".

Problem:    Syntax coloring and highlighting is in one big file.
Solution:   Move the highlighting to a separate file. (Yegappan Lakshmanan,
            closes vim/vim#4674)

https://github.com/vim/vim/commit/f9cc9f209ede9f15959e4c2351e970477c139614

Name the new file highlight_group.c instead.

Co-authored-by: zeertzjq <zeertzjq@outlook.com>