Fix deprecated implicit this capture in [=] lambdas (C++20)

[PCCV]

Summary

Replaces implicit this capture ([=]) with explicit capture ([=, this]) in lambdas defined inside member functions, across 18 files. This fixes the C++20 deprecation warning:

attention: la capture implicite de « this » via « [=] » est dépréciée en C++20 [-Wdeprecated]

Scope

• Mechanical fix, one line per occurrence, no behavior change.
• thirdparty/scintilla/src/Editor.cxx has one remaining occurrence of this warning, left untouched intentionally since it's vendored third-party code, not maintained here.

Testing

Built in Debug and Release, confirmed no more -Wdeprecated warnings outside of the vendored Scintilla file mentioned above.