Remove quotation marks from url

[Arif-Khalid]

Summary:

Fixes #340

Type of change:

• ✨ New Feature/ Enhancement

Changes Made:

• Refactor code away from JSON.parse and JSON.stringify for filters in url where possible
• Delete empty filters from url with intended behaviour to reset to default

Screenshots:

Default view URL before change

https://catcher-org.github.io/WATcher/issuesViewer?repo=catcher-org%2FCATcher
&title=""
&type="all"
&sort=%7B"active":"status","direction":"asc"%7D
&status=%5B"open%20pullrequest","merged%20pullrequest","open%20issue","closed%20issue"%5D
&milestones=%5B"V3.3.6","V3.3.7","V3.3.8"%5D&hiddenLabels=%5B%5D&deselectedLabels=%5B%5D
&labels=%5B%5D
&presetview=currentlyActive

Default view URL after change

http://localhost:4200/issuesViewer?repo=CATcher-org%2FCATcher
&type=all
&sort=%7B"active":"status","direction":"asc"%7D
&status=open%20pullrequest&status=merged%20pullrequest&status=open%20issue&status=closed%20issue
&milestones=V3.3.6&milestones=V3.3.7&milestones=V3.3.8
&presetview=currentlyActive&

Proposed Commit Message:

Quotation marks and null parameters are present for
filters saved in url.

Quotation marks are unnecessary and empty filters
can be removed from the URL in order to make it
more readable and editable by advanced users.

Let's remove null params and remove quotation marks
from the url.

Checklist:

• I have tested my changes thoroughly.
• I have created tests for any new code files created in this PR or provided a link to a issue/PR that addresses this.
• I have added or modified code comments to improve code readability where necessary.
• I have updated the project's documentation as necessary.

[NereusWB922]

LGTM!