[Admin] Release SolidusAdmin v0.0.1.alpha.1

[elia]

First alpha release of SolidusAdmin

We are committed to release an alpha version that can be used to test out our assumptions on real-world stores.
Most likely the release will take the form of a branch or a tag, with no corresponding published rubygem.

Required for the release

• [Admin] Add an auth configuration that can be attached to the existing one #5214
• [Admin] connect auth helpers to the sidebar #5293
• [Admin] Align the admin and backend menus for a transparent switch  #5271
• [Admin] add a banner for turning solidus_admin on and off #5282
• [Admin] allow to reuse or back port custom backend menu items in solidus_admin #5283
• [Admin] Refactor "accounts/show" view into a separate component #5292
• decide how to publish (branch/tag/gem/…) we'll use a branch named admin/alpha/v0
• [Admin] Add support for switching locale #5297

Nice to haves

filters/searches/scopes:

• [Admin] Implement search bar in product listing index #5257
• [Admin] Add filter toolbar for enhanced search functionality #5296
• [Admin] Add clear button visibility check for search input #5300
• [Admin] Add external id param to enhance table component flexibility #5302

[elia]

Released! #5319