Fixing timing issues in Metric Explorer UI Tests

[tpetrus]

Fixed the way that chart title is tested in ME

Description

I changed the way that the current test checks to make sure the HighCharts graph displays correctly. The issue was that the test was trying to set the title of the chart too quickly, so I modified the test to wait and change the title when it was possible.

Also modified setDateRange to properly wait until the mask disappears before setting the date.

Motivation and Context

It fixed a failed test when UI tests were run

Tests performed

Created instance of XDMoD in docker container and ran the UI Tests.

Docker container using tas-tools-ext-01.ccr.xdmod.org/centos7_6-open8.1.2:latest image. ran "~/bin/services start", then ran UI tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project as found in the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.