chore(typescript): Enable strictNullChecks for the SDK source

[krystofwoldrich]

These are enabled in JS Core since the last major v8.

Let's enable them in RN as well.

This PR should not introduce any behavior changes, only fix the null checks.

#skip-changelog

[github-actions]

Android (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	395.40 ms	392.28 ms	-3.11 ms
Size	17.75 MiB	19.54 MiB	1.80 MiB

Baseline results on branch: v7

Startup times

Revision	Plain	With Sentry	Diff
9da5c4e	478.08 ms	467.46 ms	-10.63 ms
9fbcfaf	420.06 ms	435.31 ms	15.25 ms

App size

Revision	Plain	With Sentry	Diff
9da5c4e	17.75 MiB	20.16 MiB	2.41 MiB
9fbcfaf	17.75 MiB	19.54 MiB	1.79 MiB

Previous results on branch: kw-fix-null-checks

Startup times

Revision	Plain	With Sentry	Diff
0c30894	419.04 ms	423.62 ms	4.58 ms

App size

Revision	Plain	With Sentry	Diff
0c30894	17.75 MiB	19.54 MiB	1.79 MiB

[github-actions]

Android (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	420.51 ms	432.88 ms	12.37 ms
Size	7.15 MiB	8.30 MiB	1.14 MiB

Baseline results on branch: v7

Startup times

Revision	Plain	With Sentry	Diff
9fbcfaf+dirty	417.92 ms	431.81 ms	13.90 ms
9da5c4e+dirty	399.70 ms	407.34 ms	7.64 ms

App size

Revision	Plain	With Sentry	Diff
9fbcfaf+dirty	7.15 MiB	8.29 MiB	1.14 MiB
9da5c4e+dirty	7.15 MiB	8.42 MiB	1.27 MiB

Previous results on branch: kw-fix-null-checks

Startup times

Revision	Plain	With Sentry	Diff
0c30894+dirty	398.92 ms	403.75 ms	4.83 ms

App size

Revision	Plain	With Sentry	Diff
0c30894+dirty	7.15 MiB	8.29 MiB	1.14 MiB

[github-actions]

iOS (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1215.47 ms	1219.53 ms	4.06 ms
Size	3.19 MiB	4.34 MiB	1.15 MiB

Baseline results on branch: v7

Startup times

Revision	Plain	With Sentry	Diff
9fbcfaf+dirty	1215.22 ms	1222.26 ms	7.04 ms
9da5c4e+dirty	1215.41 ms	1226.38 ms	10.97 ms

App size

Revision	Plain	With Sentry	Diff
9fbcfaf+dirty	3.19 MiB	4.34 MiB	1.15 MiB
9da5c4e+dirty	3.19 MiB	4.33 MiB	1.14 MiB

Previous results on branch: kw-fix-null-checks

Startup times

Revision	Plain	With Sentry	Diff
0c30894+dirty	1217.24 ms	1216.37 ms	-0.88 ms

App size

Revision	Plain	With Sentry	Diff
0c30894+dirty	3.19 MiB	4.34 MiB	1.15 MiB

[github-actions]

iOS (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1215.10 ms	1225.61 ms	10.51 ms
Size	2.63 MiB	3.77 MiB	1.14 MiB

Baseline results on branch: v7

Startup times

Revision	Plain	With Sentry	Diff
9fbcfaf+dirty	1216.66 ms	1212.06 ms	-4.60 ms
9da5c4e+dirty	1231.84 ms	1235.49 ms	3.65 ms

App size

Revision	Plain	With Sentry	Diff
9fbcfaf+dirty	2.63 MiB	3.77 MiB	1.14 MiB
9da5c4e+dirty	2.63 MiB	3.76 MiB	1.13 MiB

Previous results on branch: kw-fix-null-checks

Startup times

Revision	Plain	With Sentry	Diff
0c30894+dirty	1223.60 ms	1236.98 ms	13.38 ms

App size

Revision	Plain	With Sentry	Diff
0c30894+dirty	2.63 MiB	3.77 MiB	1.14 MiB

[antonis]

Thank you for enabling strictNullChecks and improving the code along the way 🎸