fix: metadata stored by 0.1.8/0.1.9 copies breaks newer copies (uniqueIndexes added without a key bump) #44

The metadata keys (Symbol.for(...@1)) are shared by every copy of the package on purpose, so that tables declared through one copy can be read through another. #32 added uniqueIndexes to DatumStaticMetadata without bumping the key, so metadata stored by a copy at 0.1.8 or 0.1.9 is read by a newer copy as if it had the new shape.

Reproduction (CommonJS; old is a 0.1.9 install, current the main build):

const oldCopy = require("<0.1.9 install>/node_modules/@antelopejs/interface-database-decorators");
const newCopy = require("@antelopejs/interface-database-decorators");
class Row extends oldCopy.Table {}
oldCopy.Index()(Row.prototype, "email");
const meta = newCopy.getMetadata(Row, newCopy.DatumStaticMetadata);
console.log("instanceof new class:", meta instanceof newCopy.DatumStaticMetadata);
console.log("uniqueIndexes:", meta.uniqueIndexes);
meta.uniqueIndexes.has("email");

Output:

instanceof new class: false
uniqueIndexes: undefined
TypeError: Cannot read properties of undefined (reading 'has')

Expected: either the key is versioned when the stored shape changes, or a reader tolerates (or upgrades) metadata stored by an older copy.