Restructured queue.py and stack.py

[HarsheetKakar]

References to other Issues or PRs or Relevant literature

Fixes #150

Brief description of what is fixed or changed

• changed front and rear to properties and changed the code accordingly.
• using _check_type() instead of checking explicitly.

[codecov]

Codecov Report

Merging #152 into master will increase coverage by 0.145%.
The diff coverage is 100%.

@@              Coverage Diff              @@
##            master      #152       +/-   ##
=============================================
+ Coverage   98.179%   98.325%   +0.145%     
=============================================
  Files           21        21               
  Lines         1593      1612       +19     
=============================================
+ Hits          1564      1585       +21     
+ Misses          29        27        -2

Impacted Files	Coverage Δ
...datastructs/miscellaneous_data_structures/queue.py	100% <100%> (ø)	⬆️
...datastructs/miscellaneous_data_structures/stack.py	100% <100%> (+5.128%)	⬆️

[czgdp1807]

Please add some tests for the lines marked red here. It will improve the diff coverage.

[HarsheetKakar]

Please add some tests for the lines marked red here. It will improve the diff coverage.
I was wondering what it was 😆

[HarsheetKakar]

@czgdp1807 can you go through it once more please? I have made the changes and LinkedListStack is on the way.

[HarsheetKakar]

since we are already restructuring the codebase. kindly check #154 too @czgdp1807

[czgdp1807]

Merging.