[Proof of Concept] Call remove_account when new account is created

[jiasli]

Fix AzureAD#335
Require AzureAD#339

Call remove_account when new account is created.

Because old access tokens are purged from the token cache, acquire_token_silent will no longer return revoked access tokens.

In other words,

• All initial logins (auth code, device code, username password) will trigger remove_account
• Silent refreshing will not trigger remove_account because of skip_account_creation=True

[chlowell]

One concern I have with this approach is that it may unintentionally invalidate the cache in normal usage. Removing an account from the cache entails removing all its associated tokens. It appears MSAL caches an account whenever it receives client_info and an ID token, and that it always requests these. I worry this might then be possible:

1. user requests a token for scope A
2. MSAL caches access token and account
3. user requests a token for scope B
4. MSAL acquires new access and ID tokens, evicts all the user's cached tokens
5. user requests a token for scope A
6. MSAL acquires new access and ID tokens, evicts all the user's cached tokens
7. user requests a token for scope B...

[jiasli]

My change will not evict all the user's cached tokens when doing cross-scope refreshing, because skip_account_creation=True is specified (AzureAD#339).

[jiasli]

The order of adding tokens to the cache matters. Always create the account first so that old account can be removed first.