Provide option to connect Crypto Wallet to be connected via private windows only

[srirambv]

Description

Current implementation, Crypto wallet page only opens in normal window(#6706 . Even though the component works on Private tabs by default, when trying to connect to a Dapp it still launches the normal window to connect

Steps to Reproduce

1. Enable CW on normal window
2. Open a private tab and visit cryptokitties.co
3. Connect wallet on private tab, connect account popup opens in a normal tab

Actual result:

Provide option to connect Crypto Wallet to be connected via private windows only

Expected result:

Should open popup window on private tab when the connection was initiated in a private tab

Reproduces how often:

Easy

Brave version (brave://version info)

All component versions

Version/Channel Information:

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the dev channel? Yes
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? N/A
• Does the issue resolve itself when disabling Brave Rewards? N/A
• Is the issue reproducible on the latest version of Chrome? N/A

Miscellaneous Information:

Related #6637
When MM is enabled to work on PT, it allows a popup on private tab itself