Show dataset name in table viewer title

[astrofrog]

Fixes #1939

[codecov]

Codecov Report

Merging #1973 into master will decrease coverage by <.01%.
The diff coverage is 84.61%.

@@            Coverage Diff             @@
##           master    #1973      +/-   ##
==========================================
- Coverage    87.5%   87.49%   -0.01%     
==========================================
  Files         244      244              
  Lines       21725    21742      +17     
==========================================
+ Hits        19010    19024      +14     
- Misses       2715     2718       +3

Impacted Files	Coverage Δ
glue/viewers/table/qt/data_viewer.py	96.85% <100%> (+0.6%)	⬆️
glue/viewers/common/qt/data_viewer.py	97.12% <100%> (+0.02%)	⬆️
glue/viewers/common/viewer.py	92.2% <100%> (ø)	⬆️
glue/core/layer_artist.py	78.03% <80%> (-0.85%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2d9c63c...5a0dfec. Read the comment docs.