refactor: enable noImplicitAny session.ts

[laljikanjareeya]

towards #223

• Tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

[codecov]

Codecov Report

Merging #697 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master    #697   +/-   ##
======================================
  Coverage    99.1%   99.1%           
======================================
  Files          12      12           
  Lines        1348    1348           
  Branches      215     215           
======================================
  Hits         1336    1336           
  Misses          4       4           
  Partials        8       8

Impacted Files	Coverage Δ
src/session.ts	97.05% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4571f15...a648d77. Read the comment docs.