local vs global chain_type (for better test isolation)

[antiochp]

Replaces #409 (closed due to merge/rebase problems).
Related mimblewimble/grin#3327

Grin PR mimblewimble/grin#3327 introduces (thread) local and global configuration of chain_type.
This PR makes the necessary changes in grin-wallet for compatibility.

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Updated grin deps for latest master -

cargo update -p grin_core
    Updating git repository `https://github.com/mimblewimble/grin`
    Updating crates.io index
    Updating grin_api v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d
    Updating grin_chain v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d
    Updating grin_core v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d
    Updating grin_keychain v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d
    Updating grin_p2p v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d
    Updating grin_pool v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d
    Updating grin_store v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d
    Updating grin_util v4.0.0-alpha.1 (https://github.com/mimblewimble/grin#93f5de3d) -> #6faa0e8d

[yeastplume]

Exact same code as earlier just passed - #417

Can you just merge from upstream once more? I've stopped the doctests running on windows, which should hopefully alleviate the problem

[yeastplume]

I just merged via the web UI, hopefully this should pass and we can move on with our lives

[antiochp]

I just merged via the web UI, hopefully this should pass and we can move on with our lives

It's weird. The CI run prior to you merging actually passed on this PR...