* Exclude headers in module map that are not included in umbrella header (SVGKit#743)

Header files not included in the umbrella header must be explicitly excluded
in the module map to avoid build warnings.

Add header excludes to eliminate the following build warnings:

Umbrella header for module 'SVGKit' does not include header 'SVGKDefine_Private.h'
Umbrella header for module 'SVGKit' does not include header 'SVGKExporterNSImage.h'
Umbrella header for module 'SVGKit' does not include header 'SVGKImageRep.h'

This allows projects that depend on the SVGKit pod to treat warnings as errors
without interference.

* Fix inline base64 image warning (SVGKit#745)

* fix: basic contentMode support for SVGKFastImageView (SVGKit#747)

* Update SVGKDefine_Private.h (SVGKit#742)

* Add Swift Package Manager installation option to README (SVGKit#757)

* Elliptical arc flag arguments might not be separated by whitespace (SVGKit#761)

Co-authored-by: Stephen Kelly <stevekelly@gmail.com>

* Update to newest version of SVGKDefine_Private.h

Co-authored-by: ap-for-work <84585026+ap-for-work@users.noreply.github.com>
Co-authored-by: Cokile Ceoi <kelvintgx@gmail.com>
Co-authored-by: farfromrefuge <dev@akylas.fr>
Co-authored-by: troZee <12766071+troZee@users.noreply.github.com>
Co-authored-by: Krzysztof Pacholak <63740434+kpacholak@users.noreply.github.com>
Co-authored-by: Stephen Kelly <stephenk@hpe.com>
Co-authored-by: Stephen Kelly <stevekelly@gmail.com>

* drjoy-v2:
  Elliptical arc flag arguments might not be separated by whitespace (SVGKit#761)
  Add Swift Package Manager installation option to README (SVGKit#757)
  Update SVGKDefine_Private.h (SVGKit#742)
  fix: basic contentMode support for SVGKFastImageView (SVGKit#747)
  Fix inline base64 image warning (SVGKit#745)
  Exclude headers in module map that are not included in umbrella header (SVGKit#743)
  Added support for hsl and hsla colors (SVGKit#731)
  Fixes SVGKit#724 - SVGKitSwift SPM build issue (when archiving only) (SVGKit#726)
  Update podspec to make unused header files private (SVGKit#720)
  Fix issues on Apple Silicon M1 (SVGKit#717)
  修复加载某些SVG图片，闪退的Bug (SVGKit#714)
  Validate Workspace: YES https://stackoverflow.com/questions/63267897/building-for-ios-simulator-but-the-linked-framework-framework-was-built/65306886#65306886 (SVGKit#709)
  Fix compilation issues on `3.x` branch (SVGKit#703)
  Update Package.swift (SVGKit#702)
  improve parsing of TransformAttributes (SVGKit#699)
  handle multiple values in lineto commands (SVGKit#698)