Fix WCDB build issue for Swift user, allow CocoaPods user to use WCDB.swift without any issue

[dreampiggy]

This PR fix many issues about current's WCDB Swift project configfuration.

1. The pod_target_xcconfig override the OTHER_SWIFT_FLAGS, which will remove the CocoaPods's injected modulemap path, cause import error when compile Swift source files.

2. The Swift code loss the symbol sqliterk_cipher_conf_set_key, which seems be the old sqliterk API. I added this one into the SQLite-Briding.h

3. Fix the non framework type (For example, CocoaPods by default use Static Library without framework) build issue. I replace the <WCDBSwift/SQLite-Bridging.h> into "SQLite-Bridging.h" to make both compatible for use_frameworks! or not.

4. Also, update the git submodule of sqlcipher. It seems the upstream already provided one Xcode project which can build. I just change the current swift/source/util/sqlcipher.xcodeproj reference with the symboliced sqlcipher/sqlcipher.preprocessed.xcodeproj, make it compilable by opening WCDB.swift.xcworkspace

After those changes above. I can easily build any Swift Demo by using the Podfile like this:

use_modular_headers!
target 'Example' do
    pod 'WCDB.swift', :git => 'https://github.com/dreampiggy/wcdb.git', :branch => 'fix_swift'
end

Provided one demo here: https://github.com/dreampiggy/WCDBSwiftDemo

Now just pod install and build just works :

Wait for your reply :)

[dreampiggy]

CC @RingoD @John-He-928

[Qiuwen-chen]

New version of WCDB Swift is released, thanks.