SQL: increase EXPR_DEPTH from 20 -> 100

[elithrar]

This PR sets the maximum expression depth to 100 as an intermediate measure, accepting that it may not unblock every user.

Background: We're seeing developers (particularly those using ORMs) run into limitations when running queries against D1. It is not clear from an EQP (EXPLAIN QUERY PLAN) output what the expression depth of a query is, which makes it challenging to set this to a value that works for users without being unnecessarily high — the deeper the expression depth the more likely the query to just run into other limits.

For context:

• The SQLite default is 1000.
• Our current is 20
• The "Dark Arts" suggested value was 10 (https://www.sqlite.org/security.html)

Fixes #4094