Extend/remove the limit of 25 context after login

[shaqian]

Description of the new feature

By default Azure PowerShell populates context for only 25 subscriptions after login.
https://github.com/Azure/azure-powershell/blob/master/src/Accounts/Accounts/Models/RMProfileClient.cs#L293

var subscriptions = ListSubscriptions(tenantId).Take(25);

The limit is hard-coded. Users have to manually run additional commands to add more subscriptions.

It'd be great to have a more flexible way for user to choose how many subscriptions to populate context for.

Proposed implementation details (optional)

Add an option for how many context to populate by default.

[cormacpayne]

@shaqian thanks for the suggestion -- is there a preference on how this should be implemented? I think there are two ways to go about this:

(1) Connect-AzAccount -PopulateAllContexts

(2) Connect-AzAccount -MaxContextsToPopulate <int>

Do you think it would be better to (1) create a context for every subscription that the user has access to, or (2) allow the user to provide how many contexts they want?

[shaqian]

Hi @cormacpayne I think 1) is better. :)

[dingmeng-xue]

Can we merge 2 parameters together. If MaxContextsToPopulate < 0, it means to load all subscriptions? @dcaro @markcowl ?

[dingmeng-xue]

@BethanyZhou , given we have no environment to accurately evaluate performance impact in large tenant, let's focus on option 2 for the time being.

recommended parameter name is -MaxContextPopulation

[BethanyZhou]

PR merged #12397