Support fetching full set of data set attributes

Also, support fetching of full list of PDS and member attributes in "Show Attributes" webview

**PDS:**
```
- dsname
- member
- blksz
- catnm
- cdate
- dev
- dsntp
- dsorg
- edate
- extx
- lrecl
- migr
- mvol
- ovf
- rdate
- recfm
- sizex
- spacu
- used
- vol
- vols
```
