Refactor bpf loader

[hzxuzhonghu]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

make the bpf loader more readable and deduplicate error handling

Which issue(s) this PR fixes: Fixes #858

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 58.33333% with 195 lines in your changes missing coverage. Please review.

Project coverage is 54.58%. Comparing base (390e845) to head (832964e). Report is 41 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/bpf/workload/sock_connection.go	62.26%	22 Missing and 18 partials :warning:
pkg/bpf/workload/sendmsg.go	58.62%	18 Missing and 18 partials :warning:
pkg/bpf/workload/sock_ops.go	59.49%	16 Missing and 16 partials :warning:
pkg/bpf/workload/xdp.go	54.54%	12 Missing and 13 partials :warning:
pkg/bpf/bpf.go	43.24%	12 Missing and 9 partials :warning:
pkg/bpf/ads/loader.go	53.12%	7 Missing and 8 partials :warning:
pkg/bpf/workload/loader.go	56.25%	0 Missing and 14 partials :warning:
pkg/bpf/ads/sock_connection.go	37.50%	0 Missing and 5 partials :warning:
pkg/bpf/restart/bpf_restart.go	66.66%	3 Missing :warning:
pkg/controller/workload/workload_controller.go	0.00%	2 Missing :warning:
... and 2 more

Files with missing lines	Coverage Δ
pkg/bpf/utils/bpf_helper.go	100.00% <100.00%> (ø)
pkg/bpf/utils/pin.go	57.57% <100.00%> (ø)
pkg/cache/v2/maps/cluster.go	56.09% <ø> (ø)
pkg/cache/v2/maps/common.go	56.09% <ø> (ø)
pkg/controller/client.go	65.43% <100.00%> (ø)
pkg/controller/workload/workload_processor.go	61.76% <ø> (ø)
pkg/utils/test/bpf_map.go	37.14% <100.00%> (-4.97%)	:arrow_down:
pkg/controller/controller.go	0.00% <0.00%> (ø)
pkg/status/status_server.go	42.30% <0.00%> (ø)
pkg/controller/workload/workload_controller.go	62.74% <0.00%> (ø)
... and 9 more

... and 4 files with indirect coverage changes

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[hzxuzhonghu]

/assign @lec-bit

[hzxuzhonghu]

cc @nlgwcy

[nlgwcy]

/lgtm /approve

[kmesh-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: nlgwcy

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• ~~OWNERS~~ [nlgwcy]

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