fix: remove dynamic spend limit configuration from sdk constructor

[stephancill]

Summary

• Removes the dynamicSpendLimit config option and enables it by default for sub accounts
• Also removes the restriction that only enables it when auto sub accounts is enabled

How did you test your changes?

Manual testing, unit tests

[cb-heimdall]

✅ Heimdall Review Status

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[montycheese]

Also removes the restriction that only enables it when auto sub accounts is enabled

Where is this change made?