[Swift] Swift implementation 🎉🎉 (#5603)

* Implemented the swift version of Flatbuffers

Implemented serailzing, reading, and mutating data from object monster

Fixes mis-aligned pointer issue

Fixes issue when shared strings are removed from table

Adds swift enum, structs code gen

Fixed namespace issues + started implementing the table gen

Added Mutate function to the code generator

Generated linux test cases

Fixed an issue with bools, and structs readers in table writer

Swift docker image added

Updated the test cases, and removed a method parameters in swift

Fixed createVector api when called with scalars

Fixed issues with scalar arrays, and fixed the code gen namespaces, added sample_binary.swift

Cleaned up project

Added enum vectors, and their readers

Refactored code

Added swift into the support document

Added documentation in docs, and fixed a small issue with Data() not being returned correctly

Fixes Lowercase issue, and prevents generating lookups for deprecated keys

* Made all the required funcs to have const + removed unneeded code + fix lowercase func

* Removed transform from lowercased and moved it to function

* Fixes an issue with iOS allocation from read

* Refactored cpp code to be more readable

* casts position into int for position

* Fix enums issue, moves scalar writer code to use memcpy

* Removed c_str from struct function

* Fixed script to generate new objects when ran on travis ci: fix

* Handles deallocating space allocated for structs

* Updated the test cases to adhere to the fileprivate lookup, no mutation for unions, and updated the names of the vector functions