Fix SPM install issue

[DenTelezhkin]

It turns out, that if you install library from branch using SPM, SWIFT_PACKAGE is defined for public headers, however if you install from tag(1.0.2 for example), SWIFT_PACKAGE is not defined for public headers, breaking compilation.

<module-includes>:1:9: note: in file included from <module-includes>:1:
#import "<redacted>/SourcePackages/checkouts/FMPFeedbackForm/FMPFeedbackForm/include/FMPFeedbackForm.h"

<redacted>/SourcePackages/checkouts/FMPFeedbackForm/FMPFeedbackForm/include/FMPFeedbackForm.h:16:9: error: 'FMPFeedbackForm/FMPFeedbackParameter.h' file not found
#import <FMPFeedbackForm/FMPFeedbackParameter.h>

To work around this limitation, I created separate FMPFeedbackForm.h file in include folder that uses quoted imports, and removed previous if from framework header, that uses angled imports.

Some useful links:

• https://forums.swift.org/t/unable-to-compile-swift-package-when-used-in-xcode/36081
• https://github.com/firebase/firebase-ios-sdk/blob/master/HeadersImports.md#header-file-types-and-locations---for-header-file-creators