Upgrade the Tabulator widget to use Tabulator JS 5.x

[maximlt]

The Tabulator widget relies on the 4.9.3 version of the Tabulator JS library while its latest version is the 5.2.7. An upgrade to Tabulator 5.x (5.0.7 at the time) was already attempted last year (https://github.com/holoviz/panel/pull/2898) but had to be reverted (https://github.com/holoviz/panel/pull/3094) as major performance hits were observed. This issue was reported to the Tabulator's maintainer (https://github.com/olifolkerd/tabulator/issues/3530) who indicated having fixed it in a subsequent release. Given the time frame since the last upgrade attempt, it appears reasonable to think that Tabulator 5 is now stable and should no longer have the performance hits that were observed.

• [ ] Before upgrading, the Tabulator widget should be covered by an extensive number of UI tests. Tabulator 5 was a major update and the widget upgrade could cause many regressions that would be difficult to catch without a proper UI test suite: https://github.com/holoviz/panel/issues/3631
• [ ] We should check that the performance hits observed with the 5.0.7 version have effectively been fixed