Bhrg/paste empty selection includes newline

[BartolHrg]

Inspired by #256039 (comment)
Depends on: #286895

Description

Add new setting: editor.pasteEmptySelectionIncludesNewline
Values:

• always (default): Both single & multiple cursors paste with '\n' when copying empty selection
• never: Both single & multiple cursors trim '\n' from the end when copying empty selection
• singleOnly: Multiple cursors trim '\n' from the end when copying empty selection
• multipleOnly: Single cursor trims '\n' from the end when copying empty selection

More detailed description:

In each case I show before and after copy-pasting with single and multiple cursors. | denotes cursor(s).

always

aa=|=

->

aa==
aa=|=

---

aa=|=
bb=|=

->

aa==
aa=|=
bb==
bb=|=

never

aa=|=

->

aa=aa==|=

---

aa=|=
bb=|=

->

aa=aa==|=
bb=bb==|=

singleOnly

aa=|=

->

aa==
aa=|=

---

aa=|=
bb=|=

->

aa=aa==|=
bb=bb==|=

multipleOnly

aa=|=

->

aa=aa==|=

---

aa=|=
bb=|=

->

aa==
aa=|=
bb==
bb=|=