Fixed scintilla interface function signatures

[mahee96]

• strictly typed C# enums were used instead of int (C/C++ enums are int)
• refer to docs for public interface signatures https://www.scintilla.org/ScintillaDoc.html

[mahee96]

This PR#72 should fix#70

[kbilsted]

you can combine enums in c# if you mark them with flags https://docs.microsoft.com/en-us/dotnet/api/system.flagsattribute?view=net-5.0

[mahee96]

Yeah that is true, but enums are typed so a enum constant acn be or'd with enum constant of same type but it won't work with another enum type constant or another type such as int. So to better maintain compatibility with existing C++ classes which the original scintilla is based upon, I suggest we better go with plain int instead of enum.

Even if we declare it as flags/FlagAttribute, it can't be added simply as we would do with int flags like in C++

0x01 + 0xFE = 0xFF (arithmetic or logical both can be applied)

As in the issue #70 the line numbers/counters might be or'd or added to the level enumeration where line numbers are int and if enum is presented, it restricts the api usage by strong param types.

Also Scintilla documentation shows the usage of int instead of enum for enumeration types.

Correct me if I am wrong in saying enums are strictly typed.

[mahee96]

Hmm seems like C# enums are not strictly classes as in java. So probably a type cast to int and declaring enum as Flag should have sufficed in first place?...interesting...