feat(rollup-relayer): add sync height and throughput metrics

[colinlyguo]

Purpose or design rationale of this PR

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 98.18182% with 1 line in your changes missing coverage. Please review.

Project coverage is 51.81%. Comparing base (736d850) to head (21d5f91).

Files with missing lines	Patch %	Lines
rollup/internal/controller/watcher/l2_watcher.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1520      +/-   ##
===========================================
+ Coverage    51.61%   51.81%   +0.19%     
===========================================
  Files          155      155              
  Lines        12780    12835      +55     
===========================================
+ Hits          6597     6651      +54     
- Misses        5609     5610       +1     
  Partials       574      574              

Flag	Coverage Δ
rollup	55.92% <98.18%> (+0.52%)	⬆️

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