Include context command functionality

[wolfo951]

With this change, there will be 3 new commands:

1. itp context info

With this command, users can check their current context information. Ex:

{ 
    "iModelId": "<iModelId>", 
    "iTwinId": "<iTwinId>"
}

2. itp context set

With this command, users will be able to set iTwinId or/and iModelId for the context to be used across the CLI

itp context set --itwin-id <iTwinId>

itp context set --itwin-id <iTwinId> --imodel-id <iModelId>

3. itp context clear

With this command, users can clear existing context so that the values would not be referenced in the upcoming command execution.

Notes:

Once the context has been set, the user can execute commands like:
itp itwin info --json and get information about the itwin that is stored in the context

Priority:

From highest to lowest:

1. Flag input (will override anything else)
2. Context input (will override environment variables)
3. Environemnt input
4. If value is not provided, command will display an exception with message requesting for a flag with a value

[Nadegamra]

Here are the problems I see with the current context set command implementation:

1. It is possible to set unrelated itwin-id and imodel-id values. This could cause failure in commands, that use both flags.
2. You are able to have only imodel-id set without having the itwin-id set. This would cause some commands to fail, when both flags are used and this situation could be avoided entirely by fetching the imodel and getting the itwin-id from there.

[wolfo951]

Here are the problems I see with the current context set command implementation:

1. It is possible to set unrelated itwin-id and imodel-id values. This could cause failure in commands, that use both flags.
2. You are able to have only imodel-id set without having the itwin-id set. This would cause some commands to fail, when both flags are used and this situation could be avoided entirely by fetching the imodel and getting the itwin-id from there.

@Nadegamra Included the auto fetch for itwin-id when only imodel-id is provided. Also added verification for both itwin-id and imodel-id

[Nadegamra]

Currently there are no integration tests for the iTwin/IModel context functionality

[wolfo951]

Currently there are no integration tests for the iTwin/IModel context functionality

Added integration tests