Use last 6 digits of external ID

[flvndvd]

Description

In #4580, we limited the external table name to 32 characters. However, we've noticed conflicts where a single Google Spreadsheet can contain multiple sheets with the same last 4 trailing digits.

To address this, this PR allows for up to 6 trailing digits to be used when constructing the table name. This could potentially make it more challenging for the model to generate queries to target those tables.

Risk

Deploy Plan

[fontanierh]

LGTM. For the model, maybe we'll want some kind of "display name" for tables, but we still need to find a way to make them "locally" unique... Maybe when we build the DB / render the schema we can just add _1, _2 etc.. if needed to dedup ?

[flvndvd]

LGTM. For the model, maybe we'll want some kind of "display name" for tables, but we still need to find a way to make them "locally" unique... Maybe when we build the DB / render the schema we can just add _1, _2 etc.. if needed to dedup ?

Seen IRL, will do in a subsequent PR.