[PropertyAccess] Removed underscores from test method names

Removed underscores from test method names to be consistent with other components. 

This was previously done in #6695, but was partly lost when merging with master (PropertyAccess component was created, so the location of tests has changed).


| Q              | A                                        |
|--------------|--------------------------------|
| Bug fix?          | no |
|New feature? | no |
|BC breaks?    | no |
|Deprecations? |	no |
|Tests pass? | yes |
|Fixed tickets | n/a |
|License | MIT |
|Doc PR | n/a |