Repository: FHIR/sushi (ts)

Issue:
RuleSets not allowing ConceptCaretRules
When attempting to use a ConceptCaretRule in a RuleSet, you receive the following error:
> error Rule of type CodeCaretValueRule cannot be applied to entity of type FshCodeSystem

It looks like we forgot to add this rule type to the "allowed rules" that RuleSet references to see what is valid.

Example:
```
Alias:   $SCT = http://snomed.info/sct

CodeSystem: SimpleSystem
Title:     "Simple System"
Description: "A simple system"
* insert ConceptWithGermanSynonym(
    #Fish,
    "Fish",
    "It is a fish",
    "Fisch")
* insert ConceptWithGermanSynonym(
    #Seal,
    "Seal",
    "It is a seal",
    "Seehund")

RuleSet: ConceptWithGermanSynonym(code, display, definition, synonym)
* {code} {display} {definition}
* {code} ^designation.language = #de
* {code} ^designation.use = $SCT#900000000000013009 "Synonym"
* {code} ^designation.value = {synonym}
```

https://fshschool.org/FSHOnline/#/share/3zeH3PT

Pull request description:
Allow CodeCaretValueRules on FSHCodeSystem and RuleSet
This fixes #833. 

We were not allowing `CodeCaretValueRules` on `FshCodeSystems` and `RuleSets`. So something like the FSH found at this [link](https://fshschool.org/FSHOnline/#/share/3zjIdK9) would not work. This PR fixes that so that the `insert` rule can apply a `CodeCaretValueRule` to both a `FshCodeSystem` and a `RuleSet`. For testing, the linked FSH exercises both cases.

Patch:
diff --git a/src/fshtypes/AllowedRules.ts b/src/fshtypes/AllowedRules.ts
index 8a00267..5bcd1b1 100644
--- a/src/fshtypes/AllowedRules.ts
+++ b/src/fshtypes/AllowedRules.ts
@@ -22,7 +22,8 @@ import {
   ConceptRule,
   ValueSetComponentRule,
   MappingRule,
-  Rule
+  Rule,
+  CodeCaretValueRule
 } from './rules';
 
 const allowedRulesMap = new Map<any, any[]>([
@@ -54,7 +55,7 @@ const allowedRulesMap = new Map<any, any[]>([
   ],
   ['Instance', [AssignmentRule]],
   ['FshValueSet', [ValueSetComponentRule, CaretValueRule]],
-  ['FshCodeSystem', [ConceptRule, CaretValueRule]],
+  ['FshCodeSystem', [ConceptRule, CaretValueRule, CodeCaretValueRule]],
   ['Mapping', [MappingRule]],
   [
     'RuleSet',
@@ -70,7 +71,8 @@ const allowedRulesMap = new Map<any, any[]>([
       ObeysRule,
       OnlyRule,
       ValueSetComponentRule,
-      BindingRule
+      BindingRule,
+      CodeCaretValueRule
     ]
   ],
   [


Test patch:
diff --git a/test/fshtypes/AllowedRules.test.ts b/test/fshtypes/AllowedRules.test.ts
index 985785e..5a5844c 100644
--- a/test/fshtypes/AllowedRules.test.ts
+++ b/test/fshtypes/AllowedRules.test.ts
@@ -14,7 +14,8 @@ import {
   InsertRule,
   ValueSetComponentRule,
   ValueSetConceptComponentRule,
-  ValueSetFilterComponentRule
+  ValueSetFilterComponentRule,
+  CodeCaretValueRule
 } from '../../src/fshtypes/rules';
 import {
   isAllowedRule,
@@ -188,6 +189,7 @@ describe('isAllowedRule', () => {
     it('should allow valid rules on a FshCodeSystem', () => {
       expect(isAllowedRule(c, new CaretValueRule('foo'))).toBeTrue();
       expect(isAllowedRule(c, new ConceptRule('foo'))).toBeTrue();
+      expect(isAllowedRule(c, new CodeCaretValueRule(['foo']))).toBeTrue();
     });
 
     it('should not allow invalid rules on a FshCodeSystem', () => {
@@ -247,6 +249,7 @@ describe('isAllowedRule', () => {
       expect(isAllowedRule(r, new MappingRule('foo'))).toBeTrue();
       expect(isAllowedRule(r, new ValueSetComponentRule(true))).toBeTrue();
       expect(isAllowedRule(r, new ConceptRule('foo'))).toBeTrue();
+      expect(isAllowedRule(r, new CodeCaretValueRule(['foo']))).toBeTrue();
     });
 
     it('should not allow invalid rules on a RuleSet', () => {