Add support for Certurl element

[gorkemg]

This PR adds support for CertUrl element in Manifest, but also adds API to add CertUrl programmatically (Issue #4803).

[dsilhavy]

Thanks @gorkemg . Some code format comments, I havent checked the functionality yet. I will let you know if I have additional comments after testing

[dsilhavy]

Please add these fields to the index.d.ts

[dsilhavy]

Do we need this or can we just convert CERT_URL programmatically to lower case?

[gorkemg]

We can drop CERT_URL_LOWER_CASE and compare the manifest element name case-insensitively (e.g. name.toLowerCase() === 'certurl'. I added both to mirror existing LA_URL handling for consistency, but it is not technically required.

[dsilhavy]

Please add the default header here:

/**
 * The copyright in this software is being made available under the BSD License,
 * included below. This software may be subject to other third party and contributor
 * rights, including patent rights, and no such rights are granted under this license.
 *
 * Copyright (c) 2013, Dash Industry Forum.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *  * Redistributions of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation and/or
 *  other materials provided with the distribution.
 *  * Neither the name of Dash Industry Forum nor the names of its
 *  contributors may be used to endorse or promote products derived from this software
 *  without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY
 *  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

[dsilhavy]

Please use hasOwnProperty syntax here to keep the code consistent

[dsilhavy]

Minor reformating:

        if (!selectedKeySystem) {
            return;
        }
        const ksString = selectedKeySystem.systemString;
        const cacheEntry = certificateCache.get(ksString);
        if (cacheEntry && (cacheEntry.applied || cacheEntry.inProgress)) {
            return;
        }
        // Gather certUrls from collected mediaInfoArr contentProtection entries matching this key system
        const preferredType = settings.get().streaming.protection.preferredCertType;
        const certCandidates = _collectCertificateUrlsForSelectedKeySystem(preferredType);
        if (!certCandidates.length) {
            return;
        }

[dsilhavy]

Minor reformating:

        if (!keySystemString || !certUrls) {
            return;
        }
        const normalized = CertUrlUtils.normalizeCertUrls(certUrls);
        if (!normalized.length) {
            return;
        }