Request History: Set dropdown value to the response instead of null

[thewheat]

• Closes: History – cannot navigate to item (1st in 2nd group) #2675, Closes [Bug] Can't switch to previous item in response history #1985, Closes INS-913
• Currently there can be cases where selecting the request history drop down returns an incorrect request
  
• This is due to code returning a null instead of the response when i == 0
• As the code uses response.id as the key it seems like we will always have a response object.

Before (current broken behaviour)

After (which this fix)

Context of the bug

• So the bug is due to this section of code
  

  insomnia/packages/insomnia-app/app/ui/components/dropdowns/response-history-dropdown.js

  Lines 125 to 137 in 5a128ed

  	return (
  	<React.Fragment>
  	<DropdownDivider>5 Minutes Ago</DropdownDivider>
  	{categories.minutes.map(this.renderDropdownItem)}
  	<DropdownDivider>2 Hours Ago</DropdownDivider>
  	{categories.hours.map(this.renderDropdownItem)}
  	<DropdownDivider>Today</DropdownDivider>
  	{categories.today.map(this.renderDropdownItem)}
  	<DropdownDivider>This Week</DropdownDivider>
  	{categories.week.map(this.renderDropdownItem)}
  	<DropdownDivider>Older Than This Week</DropdownDivider>
  	{categories.other.map(this.renderDropdownItem)}
  	</React.Fragment>

• Each .map will start at index of 0 so the first item in the new grouping would cause the issue

[CLAassistant]

All committers have signed the CLA.

[develohpanda]

Thank you for fixing this and my apologies for the delay in review, it's been quite challenging to keep up with open-source PRs, but the team is working on it. We really appreciate your time! 🙌🏽

Verified as fixed in this PR, and broken in the current stable release.