Add negative leak test for iOS

[niklasberglund]

Add a negative leak test. This is a draft PR. The implementation should almost be there, but the main issue with the test right now seems to be that getConnectedThroughRelayDateInterval is returning a longer date interval for the relay connection than expected. I believe its a bug in the test code but it could also be that the stored data is incorrect. Had to work with stored data because of the ongoing move.

To try it out run testNegativeLeaks under LeakTests. The test device must be connected to the app-team-ios-tests WiFi to be able to reach the packet capture API and firewall API.

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This change is 

[niklasberglund]

Reviewable status: 0 of 13 files reviewed, 1 unresolved discussion (waiting on @pinkisemils)

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ios/MullvadVPNUITests/Networking/StreamCollection.swift line 160 at r1 (raw file):

        }

        return DateInterval(start: startDate!, end: endDate!)

Left some illegal force unwrapping in this function which should probably be fixed 👮

[niklasberglund]

Reviewable status: 0 of 13 files reviewed, 2 unresolved discussions (waiting on @pinkisemils)

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ios/MullvadVPNUITests/Base/BaseUITestCase.swift line 110 at r1 (raw file):

        let springboard = XCUIApplication(bundleIdentifier: "com.apple.springboard")

        if springboard.buttons["Allowi"].waitForExistence(timeout: Self.shortTimeout) {

Typo "Allowi"

[niklasberglund]

Reviewable status: 0 of 13 files reviewed, 3 unresolved discussions (waiting on @pinkisemils)

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ios/MullvadVPN.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved line 0 at r1 (raw file):
Restore 😄