Incorrect highlighting for .properties files

Description of the Issue

If you put a backslash before a colon or equal sign in the key of a property in a .properties file, it doesn't recognize it as a literal colon or equal sign.

Steps to Reproduce the Issue

1. Create a .properties file
2. Write a line that says key\:abc=value and another that says key\=123:value
   example.properties.txt

Expected Behavior

The key highlighting in the first line should end on the equal sign and on the colon for the second line.

Actual Behavior

The key hightlighting actually ends in the colon for the first line and in the equal sign for the second one, meaning it didn't escape the equal sign for the first line, nor the colon for the second line

Debug Information

Notepad++ v8.1.9.3 (64-bit)
Build time : Dec 6 2021 - 19:21:37
Path : C:\Program Files\Notepad++\notepad++.exe
Command Line : "C:\Users\Chicos\Desktop\example.properties"
Admin mode : OFF
Local Conf mode : OFF
Cloud Config : OFF
OS Name : Windows 8.1 Connected Single Language (64-bit)
OS Build : 9600.20174
Current ANSI codepage : 1252
Plugins : mimeTools.dll NppConverter.dll NppExport.dll

Open the attached example.properties.txt and reproduce the two escaped-separator cases in Notepad++. Start by locating the .properties syntax-highlighting implementation or entry point. Done means the key highlighting ends at the unescaped separator in both examples, with the escaped colon or equal sign treated literally.