[typescript-angular2]: use encodeURIComponent for path parameters

[macjohnny]

Description

Currently, in the generated client code for typescript-angular2 as well as for typescript-angular,
the api service builds the API path from the base path and the endpoint path. However, path-parameters are inserted as is, which means they are not url-encoded and therefore a parameter value containing e.g. +, &, %, / etc. leads to problems.
Here is a fragment from a generated code example:

public orderOrderIdSomethingGetWithHttpInfo(orderId: number, extraHttpRequestParams?: any): Observable<Response> {
        const path = this.basePath + '/order/${orderId}/something'
                                                   .replace('${' + 'orderId' + '}', orderId);
       ...
}

Swagger-codegen version

master (2.3.0 SNAPSHOT?)

Swagger declaration file content or url

any swagger file with a path parameter, e.g.

  /pet/{petId}/uploadImage:
    post:
      summary: "uploads an image"
      operationId: "uploadFile"
      parameters:
      - name: "petId"
        in: "path"
        required: true
        type: "string"

Command line used for generation

java -jar ../modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate -l typescript-angular2 -i my-swagger-file.json

Steps to reproduce

Generate the typescript-angular2 client code with the command above and check the ...Api.ts files.

Related issues/PRs

PR #6525 resolves this issue

similar issue: #6306

Suggest a fix/enhancement

An easy fix would be to change

swagger-codegen/modules/swagger-codegen/src/main/resources/typescript-angular/api.service.mustache

Line 120 in 84bb749

.replace('${' + '{{baseName}}' + '}', String({{paramName}})){{/pathParams}};

from

const path = this.basePath + '{{{path}}}'{{#pathParams}}
                    .replace('${' + '{{baseName}}' + '}', String({{paramName}})){{/pathParams}};

to

const path = this.basePath + '{{{path}}}'{{#pathParams}}
                    .replace('${' + '{{baseName}}' + '}', encodeURIComponent(String({{paramName}}))){{/pathParams}};