Avoid rendering Approve screen before token data has been retrieved.

[NiranjanaBinoy]

Fixes: #10088

Explanation:

Issue: The approve screen gets rendered before the token Data was retrieved, resulting in errors in the console and white screen flashing before the original page renders.
Fix: The fix is to check for the tokenSymbol value before rendering the <ConfirmTransactionBase/> from confirm-approve.container.js, which in turn calls <ConfirmApproveContent/>. The check is using tokenSymbol as it is the only token data that is being used in the first rendering of <ConfirmApproveContent/>

Manual testing steps:

• Go to test-dapp
• Click on Create token, and approve the deploy transaction (ideally on a testnet)
• Wait for the transaction to be confirmed
• Click Approve tokens
• The notification window should pop up, the Approve confirmation screen renders with proper values on the first call and there is no error in the console.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[metamaskbot]

Builds ready [1b6bb53]

• builds: chrome, firefox, opera
• bundle viz: background, ui, inpage, contentscript, ui-libs, bg-libs, phishing-detect
• build viz: Build System
• code coverage: Report
• storybook: Storybook
• all artifacts

Page Load Metrics (573 ± 33 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	43	81	55	9	4
		domContentLoaded	364	649	571	69	33
		load	366	651	573	69	33
		domInteractive	364	649	571	69	33

[brad-decker]

LGTM!