Add promise/prefer-await-to-then eslint rule

[Pierre-Gilles]

Pull Request check-list

To ensure your Pull Request can be accepted as fast as possible, make sure to review and check all of these items:

• If your changes affects code, did your write the tests?
• Are tests passing? (npm test on both front/server)
• Is the linter passing? (npm run eslint on both front/server)
• Did you run prettier? (npm run prettier on both front/server)

Description of change

The goal is to recommend using async/await, and stop doing chains of Promises like Promise.then().then().then(), expect in Cypress code.

https://github.com/eslint-community/eslint-plugin-promise/blob/main/docs/rules/prefer-await-to-then.md

[cloudflare-pages]

Deploying with    Cloudflare Pages

Latest commit:	96e533a
Status:	✅  Deploy successful!
Preview URL:	https://4d0962d1.gladys-plus.pages.dev
Branch Preview URL:	https://prefer-await-to-then-eslint.gladys-plus.pages.dev

View logs

[relativeci]

Job #908: Bundle Size — 6.97MiB (0%).

7eb0b2a(current) vs 5154c19 master#905(baseline)

Metrics (1 change)

	Current Job #908	Baseline Job #905
Initial JS	3.02MiB	3.02MiB
Initial CSS	293.9KiB	293.9KiB
Cache Invalidation	0%	47.26%
Chunks	52	52
Assets	148	148
Modules	1242	1242
Duplicate Modules	2	2
Duplicate Code	0.03%	0.03%
Packages	106	106
Duplicate Packages	8	8

Total size by type (no changes)

	Current Job #908	Baseline Job #905
CSS	311.09KiB	311.09KiB
Fonts	93.55KiB	93.55KiB
HTML	13.58KiB	13.58KiB
IMG	1.64MiB	1.64MiB
JS	4.92MiB	4.92MiB
Media	0B	0B
Other	4.95KiB	4.95KiB

---

View job #908 report View master branch activity

[codecov]

Codecov Report

Base: 97.26% // Head: 97.26% // No change to project coverage 👍

Coverage data is based on head (96e533a) compared to base (5154c19).
Patch has no changes to coverable lines.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1675   +/-   ##
=======================================
  Coverage   97.26%   97.26%           
=======================================
  Files         643      643           
  Lines        9684     9684           
=======================================
  Hits         9419     9419           
  Misses        265      265           

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