EDSC-3069: Fix 508 compliance 'Missing form label' findings

[mreese84]

Please review Contribution.md before contributing to this project.

Description

Path	Finding	Location	Element
/search	Missing form label	Main search bar	<input type="text" autocomplete="off" aria-autocomplete="list" aria-controls="react-autowhatever-1" class="search-form__input" name="keywordSearch" data-test-id="keywordSearchInput" placeholder="Search for collections or topics" value="">
/search	Missing form label	Hidden form at the bottom of the page	<input type="file" multiple="multiple" class="dz-hidden-input" accept=".zip,.kml,.kmz,.json,.geojson,.rss,.georss,.xml" style="visibility: hidden; position: absolute; top: 0px; left: 0px; height: 0px; width: 0px;">
/granules	Missing form label	Granule temporal start time	<input type="text" class="form-control form-control-sm" id="granule-filters_temporal-selectiontemporal-form_start-date" placeholder="YYYY-MM-DD HH:mm:ss" autocomplete="off" value="">
/granules	Missing form label	Granule temporal end time	<input type="text" class="form-control form-control-sm" id="granule-filters_temporal-selectiontemporal-form_end-date" placeholder="YYYY-MM-DD HH:mm:ss" autocomplete="off" value="">
/projects	Missing form label	Email address	<input class="form-control input" name="Email Address" placeholder="" value="sarah.d.rogers@nasa.gov">
/projects	Missing form label	Checkbox for 'Include Metadata and Processing History'	<input class="form-check-input checkbox__input" name="Include Metadata and Processing History" type="checkbox">
/projects	Missing form label	Checkbox for 'Click to enable' under spatial subsetting	<input class="form-check-input checkbox__input" name="Click to enable" type="checkbox">
/projects	Missing form label	Temporal subsetting 'Start Date' box	<input class="form-control input" name="Start Date" placeholder="YYYY-MM-DDTHH:MM:SS" type="datetime" value="">
/projects	Missing form label	Temporal subsetting 'End Date' box	<input class="form-control input" name="End Date" placeholder="YYYY-MM-DDTHH:MM:SS" type="datetime" value="">

Files

Acceptance Criteria

Fix 'Missing form label' for all findings to be 508 compliant.