Add RequestFile to typescript-node model template (#4903)

RequestFile is defined in the [api-all.mustache
template](ac4ead9e78/modules/openapi-generator/src/main/resources/typescript-node/api-all.mustache (L29)),
and it gets used [as a special
case](ac4ead9e78/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNodeClientCodegen.java (L92))
[in the model.mustache
template](ac4ead9e78/modules/openapi-generator/src/main/resources/typescript-node/model.mustache (L21)).

When this special case is triggered and `RequestFile` is used in a model
file, Typescript complains that the type is not found.

```
TSError: Unable to compile TypeScript:
path/to/model.ts:15:16 - error TS2304: Cannot find name 'RequestFile'.

15      'myFile'?: RequestFile;
                   ~~~~~~~~~~~
```

This solution is to import `RequestFile` by adding it to the model
template.

Here is an openapi schema that would trigger this use-case:

```yaml
openapi: 3.0.0
components:
    schemas:
        IUploadMyFileBody:
            type: object
            properties:
                myFile:
                    type: string
                    format: binary
```

modules/openapi-generator/src/main/resources/typescript-node/model.mustache

@@ -1,6 +1,7 @@
 {{>licenseInfo}}
 {{#models}}
 {{#model}}
+import { RequestFile } from '../api';
 {{#tsImports}}
 import { {{classname}} } from '{{filename}}';
 {{/tsImports}}

samples/client/petstore/typescript-node/default/model/apiResponse.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * Describes the result of uploading an image resource

samples/client/petstore/typescript-node/default/model/category.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * A category for a pet

samples/client/petstore/typescript-node/default/model/order.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * An order for a pets from the pet store

samples/client/petstore/typescript-node/default/model/pet.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 import { Category } from './category';
 import { Tag } from './tag';
 

samples/client/petstore/typescript-node/default/model/tag.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * A tag for a pet

samples/client/petstore/typescript-node/default/model/user.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * A User who is purchasing from the pet store

samples/client/petstore/typescript-node/npm/model/apiResponse.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * Describes the result of uploading an image resource

samples/client/petstore/typescript-node/npm/model/category.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * A category for a pet

samples/client/petstore/typescript-node/npm/model/order.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * An order for a pets from the pet store

samples/client/petstore/typescript-node/npm/model/pet.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 import { Category } from './category';
 import { Tag } from './tag';
 

samples/client/petstore/typescript-node/npm/model/tag.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * A tag for a pet

samples/client/petstore/typescript-node/npm/model/user.ts

@@ -10,6 +10,7 @@
  * Do not edit the class manually.
  */
 
+import { RequestFile } from '../api';
 
 /**
 * A User who is purchasing from the pet store