Authentication changes

[rushtehrani]

• Update opctl auth token call to return a MD5 hash of admin token
• Update login API and UI to take a username and MD5 hash of atoken - the logic should grab the service account that has the same name as username from onepanel namespace, and its corresponding token secret value, hash the token secret value and compare it with the hashed token that is passed in.
• We need to also keep track of username in localstorage and cookie so that it can be used in the UI.

[issue-label-bot]

Issue-Label Bot is automatically applying the label kind/enhancement to this issue, with a confidence of 0.94. Please mark this comment with 👍 or 👎 to give our bot feedback!

Links: app homepage, dashboard and code for this bot.