[BUG FIX] fix Unexpected renderer encountered bug. Issue #1899, #1901

[jaykim97]

This fix addresses the following raised issues
#1901
#1899

Problem:
Unexpected renderer encountered error when Search results includes "reelShelfRenderer" or "adSlotRenderere"

Implementation:
reelShelfRenderer refers to Youtube Shorts results in Search
adSlotRenderer refers to advertisement Advertisement

In search.py::fetch_and_parse() Added new conditions to skip "reelShelfRenderer" and "adSlotRenderer"

Code Sample:

from pytube import Search
s = Search('YouTube Rewind')
print(len(s.results))

Previous Output(Error):

Unexpected renderer encountered.
Renderer name: dict_keys(['reelShelfRenderer'])
Search term: YouTube Rewind
Please open an issue at https://github.com/pytube/pytube/issues and provide this log output.
Unexpected renderer encountered.
Renderer name: dict_keys(['adSlotRenderer'])
Search term: YouTube Rewind
Please open an issue at https://github.com/pytube/pytube/issues and provide this log output.
Unexpected renderer encountered.
Renderer name: dict_keys(['reelShelfRenderer'])
Search term: YouTube Rewind
Please open an issue at https://github.com/pytube/pytube/issues and provide this log output.
17

NewOutput:

17