Fix Tabulator sorting and data initialization

[philippjfr]

• Fixes sorting of unpaginated table
• Fixes data initialization of unpaginated table

[codecov]

Codecov Report

Merging #2163 (beffeb6) into master (e8f3324) will decrease coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2163      +/-   ##
==========================================
- Coverage   83.82%   83.79%   -0.04%     
==========================================
  Files         182      182              
  Lines       21773    21773              
==========================================
- Hits        18252    18244       -8     
- Misses       3521     3529       +8     

Impacted Files	Coverage Δ
panel/tests/pane/test_base.py	88.23% <0.00%> (-11.77%)	⬇️
panel/io/reload.py	64.36% <0.00%> (-2.30%)	⬇️
panel/pane/base.py	87.89% <0.00%> (-0.90%)	⬇️

---

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 e8f3324...beffeb6. Read the comment docs.