Add i18n support

[alf0ns3]

Resolve #800 , related to systemli/ticker-frontend#695

• support for i18n, resolve Feature: add localization in fr/de #800
• fr localization
• de localization
• dayjs

[alf0ns3]

Hi @0x46616c6b , I went to translate the admin panel after the user interface 😃

All the unit tests pass except 2, but I really don't understand why they don't:

 FAIL  src/components/user/UserForm.test.tsx > UserForm > should render the component
AssertionError: expected "vi.fn()" to be called 1 times, but got 0 times
 ❯ src/components/user/UserForm.test.tsx:53:22
     51|     await userEvent.click(screen.getByRole('button', { name: 'Submit' }))
     52| 
     53|     expect(callback).toBeCalledTimes(1)
       |                      ^
     54|     expect(setSubmitting).toBeCalledTimes(2)
     55|     expect(fetchMock).toBeCalledTimes(2)

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/2]⎯

 FAIL  src/components/user/UserForm.test.tsx > UserForm > should render the component for existing user
AssertionError: expected "vi.fn()" to be called 1 times, but got 0 times
 ❯ src/components/user/UserForm.test.tsx:103:22
    101|     await userEvent.click(screen.getByRole('button', { name: 'Submit' }))
    102| 
    103|     expect(callback).toBeCalledTimes(1)
       |                      ^
    104|     expect(setSubmitting).toBeCalledTimes(2)
    105|     expect(fetchMock).toBeCalledTimes(2)

Do you have an idea?

Instead of that, most of the strings are currently localized (maybe I forgot 1 or 2).

Let me know if the nested JSON object is good for you, I let you do the de work 😉

[alf0ns3]

Across all my changes, I made a small behavioral change:

https://github.com/systemli/ticker-admin/pull/804/files#diff-42f4b889789ee3668910edee2489a6e7f95e9690f032c7ac9708c0592d592c94L107

I changed the min password length from 8 to 10 there to be consistent with the newPassword min length ( https://github.com/systemli/ticker-admin/pull/804/files#diff-d2b09d32a2dfa584556d0826d490b84f08dc69d94fcd8d7b433438b11415fcdaR76