Add optionality for parameters

This commit allows for parameters that does not require any arguments to
be provided in function calls. It changes collection syntax where
parameters are list of objects instead of primitive strings. A
parameter has now 'name' and 'optional' properties. 'name' is required
and used in same way as older strings as parameter definitions.
'Optional' property is optional, 'false' is the default behavior if
undefined. It also adds additional validation to restrict parameter
names to alphanumeric strings to have a clear syntax in expressions.

src/application/Parser/Script/Compiler/Function/SharedFunction.ts

@@ -1,15 +1,15 @@
 import { ISharedFunction } from './ISharedFunction';
+import { IReadOnlyFunctionParameterCollection } from './Parameter/IFunctionParameterCollection';
 
 export class SharedFunction implements ISharedFunction {
-    public readonly parameters: readonly string[];
     constructor(
         public readonly name: string,
-        parameters: readonly string[],
+        public readonly parameters: IReadOnlyFunctionParameterCollection,
         public readonly code: string,
-        public readonly revertCode: string,
+        public readonly revertCode?: string,
         ) {
         if (!name) { throw new Error('undefined function name'); }
         if (!code) { throw new Error(`undefined function ("${name}") code`); }
-        this.parameters = parameters || [];
+        if (!parameters) { throw new Error(`undefined parameters`); }
     }
 }