(Exchanges) Introduce validation method and small updates (#565)

* Remove pointer reference

* Fix portfolio withdraw tests

* Add nil protection in validator method to reduce prospective panics and for future outbound checking

* Updated tests

* ch order var to not ref package

* rm comparison

* Add order ID validation check

* Add exchange name validation check

* Add in test details

* fix tests

* fix linter issues

* linter issues strikes again

* linter rabbit hole

* Addr nitterinos

* Add validation variadic interface to define sets of functionality check POC

* didn't want to add an amount other than 0, didn't want to add address to exchange withdraw, didn't want to whitlist, can change if need be

* add coverage

* Add validation method options for exchange wrappers and abstracted validation into its own package

* Add validation code for structs in exchange template generation

* remove extra validation call as this is done in wrapper

* fix niterinos for examplerinos

* Add template to documentation tool and regenerated documentation

* Addr niticles

* Fix tests due to validation update

* Add more validation checks for modify/submit orders

* update tests

* fix more tests

* Add asset type to submit variable in tests and rpc call. Regen funcs.

* Add field to modify struct in tests

* applied field asset to cancel struct across project

* fix woopsy

exchanges/validate/validate.go

@@ -0,0 +1,15 @@
+package validate
+
+// Checker defines validation check functionality
+type Checker interface {
+	Check() error
+}
+
+// Check defines a validation check function to close over individual validation
+// check methods
+type Check func() error
+
+// Check initiates the Check functionality
+func (v Check) Check() error {
+	return v()
+}