fix: build errors

[dianasavvatina]

Description

Fixed build errors:

There were many similar errors like this:

src/controllers/engine.ts:75:7 - error TS7053: Element implicitly has an 'any' type because expression of type 'string' can't be used to index type '{}'.
  No index signature with a parameter of type 'string' was found on type '{}'.

75       sessions[session.topic] = session;
         ~~~~~~~~~~~~~~~~~~~~~~~

Type of change

• Chore (non-breaking change that addresses non-functional tasks, maintenance, or code quality improvements)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Draft PR (breaking/non-breaking change which needs more work for having a proper functionality [Mark this PR as ready to review only when completely ready])
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How has this been tested?

The number of failing tests has not increased.
The tests which were not executed previously as build has failed, are now passing.
Tested with

yarn build
yarn test

Checklist

• I have performed a self-review of my own code
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules