Partition selector button changes from Coalesce to Merge on NestedPartitionedDiskBackedTable load

[vbabich]

Run this snippet in Legacy Groovy DHE to open a NestedPartitionedDiskBackedTable:

t2 = db.t("LearnDeephaven", "StockQuotes")

The panel initially opens with 2 disabled buttons - Partitions and Coalesce. The buttons get enabled on load, and the Coalesce button changes to Merge. It would look a bit cleaner if the button text didn't change on load, not sure if it's possible to detect the table type early and set the initial label accordingly.

DHE Version 1.20240517.187 (64db4bb6) DHC packages v0.87.0 (tested using npm run start-community)

https://github.com/user-attachments/assets/031dc358-438b-42c4-9203-2ea3c48a71f7

[mofojed]

Likely related to #2176