feat(gas-oracle): support gas token volatile exchange rate

[yiweichi]

Purpose or design rationale of this PR

Describe your change. Make sure to answer these three questions: What does this PR do? Why does it do it? How does it do it?

Since we support using alternative gas on L2, we should include l2_gas_token/l1_gas_token price information in to gas price both ways. So here we support retrieve l2_gas_token/l1_gas_token price from binance_api, and includeit in the fee data if alternative gas token enabled.

PR title

Your PR title must follow conventional commits (as we are doing squash merge for each PR), so it must start with one of the following types:

• feat: A new feature

Deployment tag versioning

Has tag in common/version.go been updated or have you added bump-version label to this PR?

• Yes

Breaking change label

Does this PR have the breaking-change label?

• No, this PR is not a breaking change

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 2.63158% with 74 lines in your changes missing coverage. Please review.

Project coverage is 51.73%. Comparing base (e3c87e6) to head (98dcb74).
Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
rollup/internal/utils/exchange_rate.go	0.00%	32 Missing ⚠️
rollup/internal/controller/relayer/l1_relayer.go	0.00%	20 Missing and 1 partial ⚠️
rollup/internal/controller/relayer/l2_relayer.go	8.69%	20 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1526      +/-   ##
===========================================
- Coverage    52.01%   51.73%   -0.29%     
===========================================
  Files          156      157       +1     
  Lines        12974    13050      +76     
===========================================
+ Hits          6749     6751       +2     
- Misses        5641     5713      +72     
- Partials       584      586       +2     

Flag	Coverage Δ
rollup	55.33% <2.63%> (-0.88%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[colinlyguo]

lgtm.