enhance: Ensure ImportV2 waits for the index to be built and refine some logic (#31629)

[bigsheeper]

Feature Introduced:

1. Ensure ImportV2 waits for the index to be built

Enhancements Introduced:

1. Utilization of local time for timeout ts instead of allocating ts from rootcoord.
2. Enhanced input file length check for binlog import.
3. Removal of duplicated manager in datanode.
4. Renaming of executor to scheduler in datanode.
5. Utilization of a thread pool in the scheduler in datanode.

issue: #28521

pr: #31629

[codecov]

Codecov Report

Attention: Patch coverage is 85.38012% with 25 lines in your changes are missing coverage. Please review.

Project coverage is 80.79%. Comparing base (bc4a9a1) to head (2ddfc9e).
Report is 6 commits behind head on 2.4.

Additional details and impacted files

@@            Coverage Diff             @@
##              2.4   #31733      +/-   ##
==========================================
- Coverage   80.81%   80.79%   -0.02%     
==========================================
  Files         974      973       -1     
  Lines      138828   138863      +35     
==========================================
+ Hits       112193   112198       +5     
- Misses      22873    22901      +28     
- Partials     3762     3764       +2     

Files	Coverage Δ
internal/datacoord/import_util.go	86.84% <100.00%> (+0.97%)	⬆️
internal/datacoord/index_meta.go	97.64% <100.00%> (+0.05%)	⬆️
internal/datacoord/segment_manager.go	85.58% <100.00%> (-3.26%)	⬇️
internal/datacoord/server.go	72.47% <100.00%> (ø)
internal/datanode/data_node.go	79.62% <100.00%> (ø)
internal/datanode/services.go	86.04% <100.00%> (ø)
pkg/util/conc/future.go	100.00% <100.00%> (ø)
pkg/util/paramtable/component_param.go	98.36% <100.00%> (+<0.01%)	⬆️
internal/datacoord/import_scheduler.go	63.52% <92.30%> (+0.34%)	⬆️
internal/datacoord/services.go	84.41% <33.33%> (+0.24%)	⬆️
... and 3 more

... and 22 files with indirect coverage changes

[mergify]

@bigsheeper E2e jenkins job failed, comment /run-cpu-e2e can trigger the job again.

[bigsheeper]

/run-cpu-e2e

[czs007]

/approve
/lgtm

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bigsheeper, czs007

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