Publishing & verifying smart contracts fails through remix if remappings present

[nakul1010]

Describe the bug
Based on the hello bitcoin guide. Remix is not flattening smart contract as expected if the smart contract has remappings.

• Tracking issue on remix project repo.
  - Issue fixed in remix, v0.43.0 released.

[nakul1010]

The fix added should be resolved in the remix v0.43.0 release.