test: reorg #15698

Problem:
Subdirectories like "visual", "insert", "normal" encourage people to
separate *related* tests for no good reason.  Typically the _mode_ is
not the relevant topic of a test (and when it is, _then_ create
an appropriate describe() or it()).

Solution:
- Delete the various `test/functional/<mode>/` subdirectories, move
  their tests to more meaningful topics.
- Rename `…/normal/` to `…/editor/`.
  - Move or merge `…/visual/*` and `…/insert/*` tests into here where
    appropriate.
- Rename `…/eval/` to `…/vimscript/`.
  - Move `…/viml/*` into here also.

* test(reorg): insert/* => editor/mode_insert_spec.lua
* test(reorg): cmdline/* => editor/mode_cmdline_spec.lua
* test(reorg): eval core tests => eval_spec.lua

test/functional/editor/macro_spec.lua

@@ -0,0 +1,30 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local eq = helpers.eq
+local eval = helpers.eval
+local feed = helpers.feed
+local clear = helpers.clear
+local expect = helpers.expect
+local command = helpers.command
+
+describe('macros', function()
+  before_each(clear)
+  it('can be recorded and replayed', function()
+    feed('qiahello<esc>q')
+    expect('hello')
+    eq(eval('@i'), 'ahello')
+    feed('@i')
+    expect('hellohello')
+    eq(eval('@i'), 'ahello')
+  end)
+  it('applies maps', function()
+    command('imap x l')
+    command('nmap l a')
+    feed('qilxxx<esc>q')
+    expect('lll')
+    eq(eval('@i'), 'lxxx')
+    feed('@i')
+    expect('llllll')
+    eq(eval('@i'), 'lxxx')
+  end)
+end)