Apply updated gridsuite template

[Tristan-WorkGH]

Apply final version of gridsuite/gridapp-template#57

[Tristan-WorkGH]

@TheMaskedTurtle I don't remember what we decided for this statement in api-rest.ts

    const tokenCopy = token || getToken();

|| or ?? (I'm thinking for the case of an empty string)

[TheMaskedTurtle]

@TheMaskedTurtle I don't remember what we decided for this statement in api-rest.ts

    const tokenCopy = token || getToken();

|| or ?? (I'm thinking for the case of an empty string)

I think ?? would be better, the only way it is an empty string is if getToken returns an empty string, but in this case it will keep on returning empty string so it avoids doing token request everytime. If it is an empty string it means there is an authentication issue, so api requests will fail anyway.