Fix MWC: fix global chain type race and use auth for mwc713.mwc.mw

[sneurlax]

2 fixes in one, one which fixes syncing and another which fixes a crash bug

[danrmiller]

LGTM. Tested on linux.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 6.25000% with 90 lines in your changes missing coverage. Please review.
✅ Project coverage is 4.93%. Comparing base (cf7251b) to head (e99bbc0).
⚠️ Report is 1 commits behind head on staging.

Files with missing lines	Patch %	Lines
...b/wallets/wallet/impl/mimblewimblecoin_wallet.dart	0.00%	49 Missing ⚠️
...gs_view/manage_nodes_views/add_edit_node_view.dart	0.00%	37 Missing ⚠️
lib/utilities/test_mwcmqs_connection.dart	0.00%	3 Missing ⚠️
lib/models/type_adaptors/node_model.g.dart	80.00%	1 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## staging #1271 +/- ##
========================================
Coverage 4.93% 4.93% ========================================
Files 1064 1064 Lines 107980 108016 +36 ========================================
+ Hits 5328 5334 +6 - Misses 102652 102682 +30 

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[danrmiller]

I'm approving this as it improves the current state of the app, mwc will now work with this merged.

[sneurlax]

Closes #1303 now too

[sneurlax]

Have to recheck that

• users can change the password in settings if mwc changes the password on their node

[sneurlax]

followup comment: "merged. I did notice that the wallet handle var was directly accessed in places vs being ensureOpened but I think that is due to checks if the wallet is not open which should be fine as it replaces what I think was current functionality anyways. May be something to look into in the future to see if it could be hanlded a bit differently/safer"