ref: Convert SentryMetricKitIntegration to Swift

[noahsmartin]

Resolves https://linear.app/getsentry/issue/COCOA-989/refactor-sentrymetrickitintegrationm-in-swift

I converted most of this in my last PR so this just follows up to convert the rest

There is one logic change here. If MetricKit ever delivered a CPU exception event with callStackPerThread = true we would now still handle it. It's not expected to happen, but there's no reason to have a guard case specifically for it, just like we don't have any for app hangs.

[linear]

COCOA-989 Refactor `SentryMetricKitIntegration.m` in Swift

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@d069d70). Learn more about missing BASE report.
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff            @@
##             main     #7076   +/-   ##
========================================
  Coverage        ?   84.860%           
========================================
  Files           ?       459           
  Lines           ?     27517           
  Branches        ?     12135           
========================================
  Hits            ?     23351           
  Misses          ?      4124           
  Partials        ?        42           

Files with missing lines	Coverage Δ
Sources/Sentry/SentryEvent.m	98.823% <ø> (ø)
Sources/Sentry/SentrySDKInternal.m	84.647% <ø> (ø)
Sources/Sentry/SentryViewHierarchyIntegration.m	100.000% <ø> (ø)
Sources/Swift/Core/Integrations/Integrations.swift	100.000% <100.000%> (ø)
...Core/MetricKit/SentryMXCallStackTree+Parsing.swift	100.000% <100.000%> (ø)
...s/Swift/Core/MetricKit/SentryMXCallStackTree.swift	100.000% <ø> (ø)
Sources/Swift/Core/MetricKit/SentryMXManager.swift	100.000% <100.000%> (ø)
...ft/Core/MetricKit/SentryMetricKitIntegration.swift	100.000% <100.000%> (ø)
Sources/Swift/SentryDependencyContainer.swift	98.230% <ø> (ø)

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1217.36 ms	1249.70 ms	32.35 ms
Size	24.14 KiB	1.03 MiB	1.00 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
43597ba	1214.88 ms	1243.52 ms	28.65 ms
9214f4c	1223.19 ms	1246.96 ms	23.77 ms
e70670c	1223.47 ms	1238.67 ms	15.20 ms
59fc426	1240.49 ms	1256.94 ms	16.45 ms
6cb4338	1238.47 ms	1256.96 ms	18.49 ms
41c0aa8	1222.75 ms	1262.40 ms	39.65 ms
35f6d9e	1222.24 ms	1253.48 ms	31.23 ms
d6ab868	1228.98 ms	1260.51 ms	31.53 ms
ec3fc3a	1212.92 ms	1245.06 ms	32.14 ms
781f560	1232.83 ms	1263.56 ms	30.73 ms

App size

Revision	Plain	With Sentry	Diff
43597ba	23.75 KiB	880.32 KiB	856.58 KiB
9214f4c	24.14 KiB	1.02 MiB	1017.26 KiB
e70670c	23.75 KiB	975.19 KiB	951.45 KiB
59fc426	23.75 KiB	920.64 KiB	896.89 KiB
6cb4338	23.75 KiB	913.63 KiB	889.88 KiB
41c0aa8	23.75 KiB	986.80 KiB	963.05 KiB
35f6d9e	23.75 KiB	1.01 MiB	1006.48 KiB
d6ab868	24.14 KiB	1.01 MiB	1015.23 KiB
ec3fc3a	23.74 KiB	1022.75 KiB	999.01 KiB
781f560	23.75 KiB	1.02 MiB	1016.46 KiB

Previous results on branch: metricKitIntegrationSwift

Startup times

Revision	Plain	With Sentry	Diff
4224e11	1215.87 ms	1247.00 ms	31.13 ms
f3c0092	1229.67 ms	1258.32 ms	28.65 ms
7ebbb60	1216.83 ms	1249.49 ms	32.66 ms
443cbc8	1224.02 ms	1251.16 ms	27.14 ms

App size

Revision	Plain	With Sentry	Diff
4224e11	24.14 KiB	1.03 MiB	1.00 MiB
f3c0092	24.14 KiB	1.03 MiB	1.00 MiB
7ebbb60	24.14 KiB	1.03 MiB	1.00 MiB
443cbc8	24.14 KiB	1.03 MiB	1.00 MiB

[itaybre]

LGTM