Sovrn: Accept Imp.ext Bidfloor either as a number or string

[ikagotso]

purpose of this commit is to fix this issue : #3514

[github-actions]

Code coverage summary

Note:

• Prebid team doesn't anticipate tests covering code paths that might result in marshal and unmarshal errors
• Coverage summary encompasses all commits leading up to the latest one, 3e1298a

sovrn

Refer here for heat map coverage report

github.com/prebid/prebid-server/v2/adapters/sovrn/sovrn.go:28:	MakeRequests		84.6%
github.com/prebid/prebid-server/v2/adapters/sovrn/sovrn.go:134:	addHeaderIfNonEmpty	100.0%
github.com/prebid/prebid-server/v2/adapters/sovrn/sovrn.go:140:	MakeBids		84.0%
github.com/prebid/prebid-server/v2/adapters/sovrn/sovrn.go:194:	getExtBidFloor		100.0%
github.com/prebid/prebid-server/v2/adapters/sovrn/sovrn.go:212:	getTagId		100.0%
github.com/prebid/prebid-server/v2/adapters/sovrn/sovrn.go:220:	getImpIdx		100.0%
github.com/prebid/prebid-server/v2/adapters/sovrn/sovrn.go:233:	Builder			100.0%
total:								(statements)		87.5%

[bsardo]

Hi @ikagotso, we recently released PBS 3.0, more specifically v3.1.0, which updates Prebid Server package import references throughout the project from v2 to v3.
For example:

import (
    "github.com/prebid/prebid-server/v3/adapters"
)

As a result, please merge with master (no rebase) and then ensure all Prebid Server package import references in the files you’ve changed are v3 such that the test suite passes so we can resume reviewing. Thanks!