Fix repeatable dot

[s-kai273]

What this PR does / why we need it:

• [x] fix repeatable dot when previous action is insert and replace one
• [x] test codes of repeatable dot

Which issue(s) this PR fixes This PR fixes https://github.com/VSCodeVim/Vim/issues/8938

Special notes for your reviewer:

Repeatable dot of insert

• example previous action: ivar
• given text: ``(cursor is at beginning of line)
• repeatable dot: 4.
• result before fixing: vavavavarrrr
• result after fixing: varvarvarvar

Repeatable dot of replace

• example previous action: r.
• given text: aaaaa(cursor is at beginning of line)
• repeatable dot: 4.
• result before fixing: .aaaa
• result after fixing: ....a