Table preview with Enums

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```lua
Enum = {
One = 1,
Two = 2,
Three = 3
}

local s_TableEnum = {
[Enum.One] = "One",
[Enum.Two] = "Two",
[Enum.Three] = "Three"
}

local s_Table = {
[1] = "One",
[2] = "Two",
[3] = "Three"
}
```
What I get:
What I expect:

Start by reproducing the Lua example and compare the preview for s_TableEnum with s_Table. Trace the table-preview handling for enum-valued keys; done means enum-keyed entries display the same labels and values as the equivalent numeric-keyed table.

Written by the indexing model from the issue text.