Fixed BigNumber.js scoping

[MiroMargineanu]

Issue

The BigNumber configuration was not properly cleaned up in the stringIsFloat helper function, thus overwriting the configuration in other helper functions too, creating a race condition.

Reproduce

Issue exists on version 3.0.12 of sdk-dapp.

Root cause

The cause was the BigNumber.set method called globally in the stringIsFloat helper function.

Fix

Create a clone of the BigNumber instance and scope it locally, and only change the settings at a local function level.

Contains breaking changes

• No
• Yes

Updated CHANGELOG

• No
• Yes

Testing

• User testing
• Unit tests

[arhtudormorar]

changelog