Change Details

As part of ongoing effort to improve organization of functions in Cashtab, move `validation` out of the `utils/` directory and into its own directory. Update imports.

As part of ongoing effort to improve organization of functions in Cashtab, move `validation` out of the `utils/` directory and into its own directory. Update imports, move mocks as well, delete legacy mocks files in `utils/`

As part of ongoing effort to improve organization of functions in Cashtab, move `validation` out of the `utils/` directory and into its own directory. Update imports., move mocks as well, delete legacy mocks files in `utils/`