Address remaining review feedback for #14255 (#14931)

This just removes some leftover code that I forgot to remove before the merge.
Additionally I forgot to add a newly added file to our `sources` build file.

src/cascadia/TerminalSettingsEditor/Appearances.h

@@ -96,7 +96,6 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
     private:
         Model::AppearanceConfig _appearance;
         winrt::hstring _lastBgImagePath;
-        float _cachedLineHeight = 0;
     };
 
     struct Appearances : AppearancesT<Appearances>

src/renderer/base/CSSLengthPercentage.cpp

@@ -52,16 +52,6 @@ CSSLengthPercentage CSSLengthPercentage::FromString(const wchar_t* str)
     return obj;
 }
 
-CSSLengthPercentage::ReferenceFrame CSSLengthPercentage::GetReferenceFrame() const noexcept
-{
-    return _referenceFrame;
-}
-
-float CSSLengthPercentage::Resolve(float factor) const noexcept
-{
-    return _value * factor;
-}
-
 float CSSLengthPercentage::Resolve(float fallback, float dpi, float fontSize, float advanceWidth) const noexcept
 {
     switch (_referenceFrame)

src/renderer/base/sources.inc

@@ -24,6 +24,7 @@ PRECOMPILED_CXX         = 1
 PRECOMPILED_INCLUDE     = ..\precomp.h
 
 SOURCES = \
+    ..\CSSLengthPercentage.cpp \
     ..\FontInfo.cpp \
     ..\FontInfoBase.cpp \
     ..\FontInfoDesired.cpp \

src/renderer/inc/CSSLengthPercentage.h

@@ -23,8 +23,6 @@ struct CSSLengthPercentage
 
     static CSSLengthPercentage FromString(const wchar_t* str);
 
-    ReferenceFrame GetReferenceFrame() const noexcept;
-    float Resolve(float factor) const noexcept;
     float Resolve(float fallback, float dpi, float fontSize, float advanceWidth) const noexcept;
 
 private: