Remove Sled crypto store, use SQLite by default

[AndrewFerr]

on account of it being removed from the crypto-sdk

Signed-off-by: Andrew Ferrazzutti andrewf@element.io

Checklist

• Tests written for all new code
• Linter has been satisfied
• Sign-off given on the changes (see CONTRIBUTING.md)

[turt2live]

I'm honestly more inclined to replace the rust-sdk with something else. These zero-notice and breaking changes are becoming more hassle than it's worth.

A migration path needs to be present for this SDK to drop sled, and the SDK will need to automatically do it in order to avoid a breaking change itself.

[AndrewFerr]

A migration path needs to be present for this SDK to drop sled, and the SDK will need to automatically do it in order to avoid a breaking change itself.

I've opened an issue to track this: element-hq#26

[turt2live]

It looks like the rust-sdk bindings have stablized a bit since this was opened, which is great. I'm tempted to land this in a v1.0.0 of the bot-sdk, as it's a breaking change.