Remove SQLite foreign key enforcement code

[bricelam]

I believe it's enabled by default in e_sqlite3. We should investigate and remove our code in 3.0

[ajcvickers]

Note: if we decide not to do this for 3.0, then we should look again at #13054

[bricelam]

Need to discuss our options...

Library	DEFAULT_FOREIGN_KEYS
e_sqlite3	✔
iOS	❌
sqlcipher	✔
winsqlite3	❌
sqlite3	❌

[ajcvickers]

Tentative decision from triage: change to reference a different bundle. This means that there will be a consistent experience across all platforms, but the version already installed on the device may not be used by default.

[bricelam]

@ericsink Any words of caution? We’re planning on switching to SQLitePCLRaw.bundle_e_sqlite3 in 3.0.

[ericsink]

No caution from me. In my experience, using the system SQLite in a cross-platform situation causes nothing but trouble (and, admittedly, smaller binary size).

FWIW, if you were to peer into my repo right now, you would see that I have recently made some changes to the way e_sqlite3 builds are done and managed. I moved the builds out into a separate repo and made a number of improvements. This includes an attempted fix for the load_extension problem you were having with the spatial library. And an update to SQLite 3.25.x.

This work needs more testing before I release it, and I had to set it aside 2-3 weeks ago to deal with something else, but I expect my schedule flexibility to return soon and allow me to get a new release published in the next couple weeks.