refactor: DAG algorithm based state management

[ra1028]

Pull Request Type

• Bug fix
• New feature
• Refactoring
• Documentation update
• Chore

Issue for this PR

Link: close #20

Description

Implement Directed Acyclic Graph based dependency graph for better reliability, predictable result, and reproducibility of the internal state.

Motivation and Context

Currently, the core system of this library is implemented with ARC and reactive programing, but it's not 100% reliable and reproducible, it prevents restoration to a specific state.
Using DAG data structure and allows this library to manage a centralized state in a holistic approach.
That's the same approach with Recoil which that this library is inspired.

Impact on Existing Code

It contains a lot of braking changes on ABI, but the existing codes written with a proper usage of Atoms should work without changes.

Performance

• Measure (average of 10 times run)
  • Main branch: 0.589 sec
  • DAG branch: 0.425 sec

= 139% better

func testPerformance() {
    struct Test1Atom: StateAtom, Hashable {
        func defaultValue(context: Context) -> Int {
            0
        }
    }

    struct Test2Atom: ValueAtom, Hashable {
        func value(context: Context) -> Int {
            context.watch(Test1Atom())
        }
    }

    struct Test3Atom: ValueAtom, Hashable {
        func value(context: Context) -> Int {
            context.watch(Test2Atom())
        }
    }

    struct Test4Atom: ValueAtom, Hashable {
        func value(context: Context) -> Int {
            context.watch(Test3Atom())
        }
    }

    struct Test5Atom: ValueAtom, Hashable {
        func value(context: Context) -> Int {
            context.watch(Test4Atom())
        }
    }

    measure {
        for _ in 0..<10000 {
            let context = AtomTestContext()

            let value0 = context.watch(Test5Atom())
            XCTAssertEqual(value0, 0)

            context[Test1Atom()] = 1

            let value1 = context.watch(Test5Atom())
            XCTAssertEqual(value1, 1)
        }
    }
}