[Enhancement] Add datacache memory tracker to trace the datacache memory usage. (backport #38884)

[GavinMar]

Why I'm doing:
The datacache memory usage is unobservable, which brings difficulties to analyze process memory details.

What I'm doing:
Add datacache memory tracker to trace the datacache memory usage.
You can observe the datacache memory usage by follow urls:

http://${BE_HOST}:${BE_WEBSERVER_PORT}/mem_tracker
http://${BE_HOST}:${BE_WEBSERVER_PORT}/metrics

What type of PR is this:

• BugFix
• Feature
• Enhancement
• Refactor
• UT
• Doc
• Tool

Does this PR entail a change in behavior?

• Yes, this PR will result in a change in behavior.
• No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

• Interface/UI changes: syntax, type conversion, expression evaluation, display information
• Parameter changes: default values, similar parameters but with different default values
• Policy changes: use new policy to replace old one, functionality automatically enabled
• Feature removed
• Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function
• This is a backport pr

Bugfix cherry-pick branch check:

• I have checked the version labels which the pr will be auto-backported to the target branch
  • 3.2
  • 3.1
  • 3.0
  • 2.5

[github-actions]

[FE Incremental Coverage Report]

✅ pass : 0 / 0 (0%)

[github-actions]

[BE Incremental Coverage Report]

❌ fail : 7 / 19 (36.84%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	src/http/default_path_handlers.cpp	0	2	00.00%	[163, 164]
🔵	src/block_cache/starcache_wrapper.cpp	0	1	00.00%	[58]
🔵	src/common/daemon.cpp	0	9	00.00%	[154, 212, 215, 216, 217, 220, 226, 227, 233]
🔵	src/block_cache/block_cache.cpp	4	4	100.00%	[]
🔵	src/block_cache/kv_cache.h	1	1	100.00%	[]
🔵	src/runtime/exec_env.cpp	1	1	100.00%	[]
🔵	src/util/system_metrics.cpp	1	1	100.00%	[]