Change pending amount occurrences to strings across application - Closes #2957

[michielmulders]

What was the problem?

A custom schema had been defined in z_schema to apply validation for certain numbers in the genesis file like fee, totalFee, and reward. For the sake of better validation and consistency, this should be converted to strings.

How did I fix it?

Modified genesis files
Modified JSON schema
Modified affected files

How to test it?

Start any network.

Review checklist

• The PR resolves Change pending amount occurrences to strings across application #2957
• All new code is covered with unit tests
• All new code was formatted with Prettier
• Linting passes
• Tests pass
• Commit messages follow the commit guidelines
• Documentation has been added/updated

[nazarhussain]

@michielmulders This change seems good, but few unit tests are failing not related to this change. Can you debug what's wrong with those tests.

[michielmulders]

@nazarhussain Found the problem, tests should be passing now.