Request dependency is deprecated and presents a warning in builds

There are a few dependency deprecated warnings when installing oav.

```plaintext
npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated
npm WARN deprecated request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
npm WARN deprecated har-validator@5.1.5: this library is no longer supported
npm WARN deprecated core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
npm WARN deprecated istanbul@0.4.5: This module is no longer maintained, try this instead:
npm WARN deprecated npm i nyc
npm WARN deprecated Visit https://istanbul.js.org/integrations for other alternatives.
npm WARN deprecated viz.js@2.1.2: no longer supported
npm WARN deprecated request-promise-native@1.0.9: request-promise-native has been deprecated because it extends the now deprecated request package, see https://github.com/request/request/issues/3142
npm WARN deprecated left-pad@1.3.0: use String.prototype.padStart()
C:\npm\prefix\oav -> C:\npm\prefix\node_modules\oav\dist\cli.js

> core-js@2.6.11 postinstall C:\npm\prefix\node_modules\oav\node_modules\core-js
> node -e "try{require('./postinstall')}catch(e){}"

Thank you for using core-js ( https://github.com/zloirock/core-js ) for polyfilling JavaScript standard library!

The project needs your help! Please consider supporting of core-js on Open Collective or Patreon:
> https://opencollective.com/core-js
> https://www.patreon.com/zloirock

Also, the author of core-js ( https://github.com/zloirock ) is looking for a good job -)

```

See

Start by inspecting the package manifests and dependency tree used when installing oav, focusing on the deprecated request chain and the other warnings listed in the issue. Confirm which direct dependencies introduce them and run the project’s installation or build checks after updating supported replacements; done means the reported deprecation warnings are resolved without breaking the CLI.

Written by the indexing model from the issue text.