modal_autoclosable: close on highlighting text

If you start highlight text and stopping the highlighting outside of elem `content` then in the` pointerclick` `event.target` will be the parent node of the `content` element, and as a result the modal closes.

[Here](https://github.com/rtemred/project-stub/blob/bug/modal_autoclosable/desktop.bundles/modal_autoclosable/modal_autoclosable.bemjson.js) can be repeated: hold down mouse button and with the mouse movement highlight the text in title or input/textarea from left to right and let go of the mouse button the mouse button outside the `content` element - modal closes.
In Firefox, it is not always possible to repeat with input and textarea, but with simple text regularly, in Chrome - without much difference.

Start with desktop.bundles/modal_autoclosable/modal_autoclosable.bemjson.js and reproduce the issue by highlighting title or input/textarea text, then releasing outside the content element in Chrome and Firefox. Trace the pointerclick target when selection ends outside content; done means highlighting text and releasing outside content no longer closes the modal.

Written by the indexing model from the issue text.