CB-13592 Fixed bug where comment is not removed on removing embedded frameworks.

[kelvinhokk]

Currently after adding an embedded framework, 4 entries are added to the PBXBuildFileSection.

        "128CD4F705D24987A12F213E": {
          "isa": "PBXBuildFile",
          "fileRef": "021AA25C78F942DA94C24904",
          "fileRef_comment": "EmbedThirdParty.framework"
        },
        "128CD4F705D24987A12F213E_comment": "EmbedThirdParty.framework in Frameworks",
        "B9B17AE7AA7C4663BA933B64": {
          "isa": "PBXBuildFile",
          "fileRef": "021AA25C78F942DA94C24904",
          "fileRef_comment": "EmbedThirdParty.framework",
          "settings": {
            "ATTRIBUTES": ["CodeSignOnCopy"]
          }
        },
        "B9B17AE7AA7C4663BA933B64_comment": "EmbedThirdParty.framework in Embed Frameworks",

After calling removeFramework function, the current existing code will incorrectly leave a orphan entry in the PBXFileSection:

        "B9B17AE7AA7C4663BA933B64_comment": "EmbedThirdParty.framework in Embed Frameworks",

This pull request fixes this issue, and adds a relevant unit test in removeFramework.js