Build Import Validation phase as the first step of compilation phases

[afsalthaj]

Here we make sure that, all of the imports are valid based on the component metadata that was passed into one of the stages of initial phase within the set of compilation phases. We also make sure to avoid duplicate imports

i.e

    pub fn infer_types_initial_phase(
        &mut self,
        function_type_registry: &FunctionTypeRegistry,
    ) -> Result<Scope, Vec<String>> {
        self.validate_imports();  // Here is where we add this validation
        self.bind_types();
        self.bind_variables_of_list_comprehension();
        self.bind_variables_of_list_reduce();

        .......
    }

Introduce a Scope struct such that initial_phase can return a Scope that's probably mutable. For now, it can be kept as simple as

struct Scope {
   functions: Vec<Functions>;

}

struct  Function {
  alias: Option<String>
  analysed_function: AnalysedExport
}