Enable strictPropertyInitialization in TypeScript configs (#16671)

[4rayaditya]

Summary

Enables TypeScript's strictPropertyInitialization compiler flag in both web and native configurations to enforce proper class property initialization, improving type safety and catching potential undefined property access at compile time.

Changes Made

1. TypeScript Configuration Updates

• tsconfig.web.json: Set strictPropertyInitialization: true
• tsconfig.native.json: Set strictPropertyInitialization: true

2. Property Initialization Fixes (19 files)

All class properties have been updated to satisfy the strict initialization requirement using two approaches:

Approach A: Direct Initialization - For properties with simple default values:

// Before
_mounted: boolean;

// After
_mounted: boolean = false;

Approach B: Definite Assignment Assertion (!) - For properties initialized in lifecycle methods or abstract properties:

// Before
_init: PromiseWithResolvers<any>;

// After - Property is initialized in componentDidMount
_init!: PromiseWithResolvers<any>;

[jitsi-jenkins]

Hi, thanks for your contribution!
If you haven't already done so, could you please make sure you sign our CLA (https://jitsi.org/icla for individuals and https://jitsi.org/ccla for corporations)? We would unfortunately be unable to merge your patch unless we have that piece :(.

[4rayaditya]

I separated the two issues into two separate PR. Extremely sorry for my unprofessional approach.
@saghul

[4rayaditya]

@saghul could you please run the tests again as the Android SDK build problem has been solved in another PR.

[saghul]

Can you please rebase, now that the CI is fixed?

[4rayaditya]

@saghul done

[4rayaditya]

@saghul @Calinteodor still I am getting this issue.
Previously it was in during cd Android but that part cleared and now it's in post cd part

[saghul]

I retried the job, looks like it got stuck in the next step, but the build was succesful.

[4rayaditya]

@saghul Thanks for helping me out.

[4rayaditya]

Hey @saghul, if you have a moment, could you provide some guidance on why this PR has not been merged? This will help me learn a lot on how open source actually works.

[saghul]

Jenkins please test this please.