chore(wallet): Don't Fetch Prices for 0 Balances

[Douglashdaniel]

Description

For better optimization and to prevent unnecessary api calls, we no longer fetch Prices and PriceHistory for a users visibleAssets that have a 0 balance.

Resolves brave/brave-browser#20280

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[srirambv]

Verification passed on

Brave	1.36.31 Chromium: 97.0.4692.71 (Official Build) nightly (arm64)
Revision	adefa7837d02a07a604c1e6eff0b3a09422ab88d-refs/branch-heads/4692@{#1247}
OS	macOS Version 12.1 (Build 21C52)

• Verified steps from PR description
• Verified there is no fetch price call done to ratios server when the wallet balance is 0 on a new wallet
• Verified selecting ETH performs a fetch price call even when ETH balance is 0
• Verified selecting BAT performs a fetch price call even when BAT balance is 0
• Verified locking and unlocking the wallet on a zero balance wallet doesn't do any more fetch calls
• Verified quit and relaunch browser doesn't do a fetch call on a zero balance wallet
• Verified if there is wallet balance then appropriate call is done on the above scenarios to get the price balance

Clean Wallet Launch	ETH Fetch Price	BAT Fetch Price	Lock Wallet/Restart browser