[Typescript] gets package npm version from API specification

[karismann]

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh, ./bin/openapi3/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\. If contributing template-only or documentation-only changes which will change sample output, be sure to build the project first.
• Filed the PR against the correct branch: master, 4.1.x, 5.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language.
  @TiFu (2017/07) @taxpon (2017/07) @sebastianhaas (2017/07) @kenisteward (2017/07) @Vrolijkx (2017/09) @macjohnny (2018/01) @nicokoenig (2018/09) @topce (2018/10)

cc @lalau

Description of the PR

same as PR #2810 but for all typescript generator :

• If no npmVersion is provided in additional properties, version from API specification is used. If none of them is provided then fallbacks to default version (1.0.0)
• Refactoring npmName, npmVersion and Snapshot cliOptions (now defined in Abstract Class)

[macjohnny]

LGTM
Thanks!