fix: [#2745] Fix current eslint warnings - botbuilder library

[ceciliaavila]

Addresses #2745
#minor

Description

This PR fixes the ESLint and JSDoc issues in the botbuilder library.

Note: we excluded the @typescript-eslint/no-explicit-any and @typescript-eslint/explicit-module-boundary-types to tackle those issues as a separated task as they require deeper analysis and testing.

Specific Changes

• Applied the eslint auto-fix with yarn lint --fix (quotes, spacing, replaced var with let)
• Added missing JSDoc documentation in methods.
• Removed unused imports and variables.

Testing

All tests passes after the changes.

[coveralls]

Pull Request Test Coverage Report for Build 1775496719

• 30 of 32 (93.75%) changed or added relevant lines in 6 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.003%) to 84.546%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
libraries/botbuilder/src/botFrameworkAdapter.ts	24	26	92.31%

Files with Coverage Reduction	New Missed Lines	%
libraries/botbuilder-lg/src/templateExtensions.ts	1	84.48%

Totals
Change from base Build 1775491407:	-0.003%
Covered Lines:	19668
Relevant Lines:	22036

---

💛 - Coveralls