fix(ios): no blurred images in image picker

[JakubPawlak]

Fix for displaying blurred images in image picker when the root view of the app is any layout nesting TabView.
Branch on which there is a reproduced bad behaviour is here:
https://github.com/JakubPawlak/nativescript-imagepicker/tree/blur

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• All existing tests are passing
• Tests for the changes are included

What is the current behavior?

In some specific cases, image picker is showing blurred images.
#195

What is the new behavior?

No blurred images.

Fixes #195

No migration steps.

[lini]

The CI build for this PR failed because the changed code references tns-core-modules version 4+ and the plugin's package.json is still configured to use version 3:

"tns-core-modules": "^3.1.0",
"tns-platform-declarations": "^3.1.0",

You should either update the references in package.json or make the code work without them. The error at the moment is:

$ tsc
imagepicker.ios.ts:31:46 - error TS2339: Property 'viewController' does not exist on type 'View'.

31         return this.hostView ? this.hostView.viewController : UIApplication.sharedApplication.keyWindow.rootViewController;
                                                ~~~~~~~~~~~~~~

[JakubPawlak]

Can I make a test CI build myself?

[lini]

The CI is public and you can view the results by going directly to https://travis-ci.org/NativeScript/nativescript-imagepicker/pull_requests
Each time you make changes to the PR, a new build will be triggered but it might take some time for it to finish, since it runs on a shared environment along with other open-source projects.

[JakubPawlak]

Ok, so I fixed package.json versions but now there are errors during UI tests... Any hints how to fix them?

[zbranzov]

@JakubPawlak Unfortunately, our tests use env variables that are not exposed by PR made from forks https://docs.travis-ci.com/user/pull-requests#pull-requests-and-security-restrictions. I will test your branch and merge it manually.

[zbranzov]

https://saucelabs.com/beta/tests/5c852405baa6461d8385c6fbe447e797/commands#29
https://saucelabs.com/beta/tests/efffc2c7a84d47de8e5e9d1572450743/commands#30
Tests pass so I will merge this PR