Add isDisplayed() as an alias command for isVisible() in new Element API.

[garg3133]

Description of the bug/issue

For the newly added .isVisible() command on the new Element API, we should also add .isDisplayed() as an alias to it, so that we can use either browser.element().isVisible() or browser.element().isDisplayed() in our tests. .isDisplayed() is the standard command name in Selenium for checking the "visibility" of an element.

Steps to reproduce

Go to ecosia.js test in examples/tests directory and add browser.element('input[name=q]').isDisplayed(); at the top of the first test case (it block). You will see an error that browser.element(...).isDisplayed is not a function.

But if you replace isDisplayed() with isVisible() it will work fine.

So, we need to get isDisplayed() command working as well, similar to the isVisible() command, without the need to add any new file in the codebase.

TODO

• Add isDisplayed as an alias to isVisible command.
• Add some more test cases to test isDisplayed alias to the already present web-element/testIsVisible.js test file.
• Add types and tests for types.

[uditrajput03]

@garg3133 I have to write just one test case for IsDisplayed() into testIsVisible.js file or just replicate all that are present in that file

[Ritika8081]

@garg3133 please have a look on my PR Added isDisplayed() as an alias command for isVisible() in new Element API and added extra test cases #4109

[AritraLeo]

@garg3133 Please have a look at my PR. I have tested the feature and ran the tests similar to isVisible(). Tests are passing for all provided cases.

[rampantvoid]

Generated a pull request. Completed all the TODO's, also ran tests locally and tried to reproduce the bug after making changes, no error was generated. Please have a look at my PR. @garg3133

[garg3133]

Assigning this issue to @uditrajput03 as he's the first one to come up with the correct solution for the issue.