stop parsing symbol only ends at end of line, but pipe character is also acceptable

Start with the PowerShell tmLanguage stop-parsing rule shown in the issue and compare it with the about_Parsing behavior. Verify that parsing ends at a pipe only when the pipe is outside double-quoted constructs, while the existing end-of-line behavior remains unchanged.

Environment

• Editor and Version: VS Code: 1.26.1
• Your primary theme: Monokai Dimmed

Issue Description

the stop parsing symbol, --% is set to scope all the way to the end of the line. I thought this was how the symbol worked as well, until I reread the doc on the matter (about_Parsing) and instead, it also can be terminated by the pipe character, but only if the pipe would be outside of any double-quoted constructs, as I have determined.

Its also possible to use environment variable substitution using the CMD `%variable% syntax, but if your environment variable name contains a double-quote, PowerShell processes it first, before the substitution has occurred (if it even occurs, as just like in CMD, if the variable is not found, the substitution does not occur), so its actually impossible to determine a real variable reference.

Expected Behavior

Syntax should at least support stop-parsing symbol's scope ending at a pipe, in the same manner as PowerShell actually does.

Possible tmLanguage modification:

{
	"begin": "(?<!\\w)(--%)(?!\\w)",
	"beginCaptures": {
		"1": {
			"name": "keyword.control.powershell"
		}
	},
	"end": "$|\\|",
	"patterns": [
		{
			"match": "[^\"\\x{201C}\\x{201D}]+?",
			"name": "string.unquoted.powershell"
		},
		{
			"begin": "(?:\"|\\x{201C}|\\x{201D})",
			"beginCaptures": {
				"0": {
					"name": "punctuation.definition.string.begin.powershell"
				}
			},
			"end": "(?:\"|\\x{201C}|\\x{201D})(?!\"|\\x{201C}|\\x{201D})|$",
			"endCaptures": {
				"0": {
					"name": "punctuation.definition.string.end.powershell"
				}
			},
			"name": "string.quoted.double.powershell"
		}
	],
	"comment": "This should be moved to the repository at some point."
},

I have the Unicode double-quotes included, as I determined that PowerShell treats them the same here as well as elsewhere.

I do have the intention of putting this in a PR.