Optimize unit test 'Edit configurations...'

[DmitriyLPexlify]

Use case:

1. User has some 'Apex unit tests' configuration.
2. Click in toolbar 'Edit configurations'

Actual results:

1. 'Finding unit tests' progress bar is shown twice (is search triggered 2 times?)
2. Test Classes view is scrolled to the top.

Expected results:

1. 'Finding unit tests' is triggered once (can test methods/classes cached until changed?).
2. Tests view is scrolled to 1st enabled test in given run configuration (Use case: User wants to enable 1 more test method in the same class - now user has to search for that test class to enable 1 more method)

[Scott Wells]

Fix submitted for inclusion in 1.7.9.8.

[Scott Wells]

Delivered in 1.7.9.8.