Improve log tracing by sending 'X-VMWARE-VCLOUD-CLIENT-REQUEST-ID' header

[Didainius]

This PR improves log traceability using VCD built-in functionality.

About the functionality itself

Whenever an HTTP client sends header X-Vmware-Vcloud-Client-Request-Id with a request, the response will have header X-Vmware-Vcloud-Request-Id that has a prefix (up to 128 chars) of what was sent to X-Vmware-Vcloud-Client-Request-Id and additionally a suffix of hypen and UUIDv4.

More about this in VCD docs: https://vdc-download.vmware.com/vmwb-repository/dcr-public/6ac8164c-8844-4188-ac1b-cd59721c06b8/7d36e490-310e-4485-91cc-c3abb23b0d32/GUID-0EAF1523-CA02-41FC-A7F3-B103108F5E4A.html

This is very useful for troubleshooting logs (especially when a lot of things are going in parallel like in the case of Terraform provider). It makes it easy to always find response to a particular request by simply searching of the part being sent.

X-Vmware-Vcloud-Client-Request-Id: [1-2024-04-13-01-58-25-733-]
X-Vmware-Vcloud-Request-Id: [1-2024-04-13-01-58-25-733--1a4df440-bf75-4317-b6a1-f0df2c9602a7]

Features in this PR

This PR adds infrastructure to send X-Vmware-Vcloud-Client-Request-Id header and also a function VcloudRequestIdBuilderFunc that can create X-Vmware-Vcloud-Client-Request-Id headers in such format {sequence-number}-{date-time-hyphen-separated}-. The sequence number is an uint64 that can support values up to 1844674407370955161518446744073709551615. The advantage of a sequence number is that it can help to understand order of requests going (and provide some sort of stats of total API requests made in the life of a program).

Longer example:

2024/03/22 13:46:56 --------------------------------------------------------------------------------
2024/03/22 13:46:56 Request caller: govcd.(*VCDClient).GetAdminOrgByName-->govcd.(*VCDClient).GetAdminOrgByName-->govcd.(*Client).executeRequest-->govcd.executeRequestWithApiVersion-->govcd.executeRequestCustomErr-->govcd.(*Client).NewRequestWithApiVersion-->govcd.executeRequestCustomErr-->govcd.(*Client).newRequest
2024/03/22 13:46:56 GET https://HOST/api/admin/org/087a027e-f3c0-4fc8-8184-d1cc691ec254
2024/03/22 13:46:56 --------------------------------------------------------------------------------
2024/03/22 13:46:56 Req header:
2024/03/22 13:46:56 	X-Vmware-Vcloud-Token-Type: [Bearer]
2024/03/22 13:46:56 	Authorization: [********]
2024/03/22 13:46:56 	User-Agent: [terraform-provider-vcd/test (darwin/arm64; isProvider:true)]
2024/03/22 13:46:56 	X-Vmware-Vcloud-Client-Request-Id: [1-2024-04-13-01-58-25-733-]  <---- Request being sent. Sequence number 1 followed by UUID
.......
################################################################################
2024/03/22 13:46:57 Response caller vcd.resourceVcdNsxtIpSetCreate-->vcd.resourceVcdNsxtIpSetRead-->vcd.(*VCDClient).GetAdminOrgFromResource-->vcd.(*VCDClient).GetAdminOrg-->govcd.(*VCDClient).GetAdminOrgByName-->govcd.(*VCDClient).GetAdminOrgByName-->govcd.(*Client).executeRequest-->govcd.decodeBody
2024/03/22 13:46:57 Response status 200 OK
2024/03/22 13:46:57 ################################################################################
2024/03/22 13:46:57 Response header:
2024/03/22 13:46:57 	X-Vmware-Vcloud-Request-Id: [1-2024-04-13-01-58-25-733--1a4df440-bf75-4317-b6a1-f0df2c9602a7] <---- Response that is prefixed by all the data that was sent in request X-Vmware-Vcloud-Client-Request-Id
2024/03/22 13:46:57 	Cache-Control: [no-store, must-revalidate]
2024/03/22 13:46:57 	Date: [Fri, 22 Mar 2024 11:46:57 GMT]
2024/03/22 13:46:57 	X-Vmware-Vcloud-Ceip-Id: [463fac1b-382b-4117-a7ca-ebd5c20a1595]
2024/03/22 13:46:57 	Content-Type: [application/vnd.vmware.admin.organization+xml;version=37.0]
2024/03/22 13:46:57 	X-Vmware-Vcloud-Request-Execution-Time: [432]
2024/03/22 13:46:57 	Vary: [Accept-Encoding]
2024/03/22 13:46:57 Response text: [72504]
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<AdminOrg xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:vmext="http://www.vmware.com/vcloud/extension/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1" xmlns:vssd="http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_VirtualSystemSettingData" xmlns:common="http://schemas.dmtf.org/wbem/wscim/1/common" xmlns:rasd="http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_ResourceAllocationSettingData" xmlns:vmw="http://www.vmware.com/schema/ovf" xmlns:ovfenv="http://schemas.dmtf.org/ovf/environment/1" xmlns:ns9="http://www.vmware.com/vcloud/versions" name="dserplis" id="urn:vcloud:org:087a027e-f3c0-4fc8-8184-d1cc691ec254" href="https://HOST/api/admin/org/087a027e-f3c0-4fc8-8184-d1cc691ec254" type="application/vnd.vmware.admin.organization+xml">
    <Link rel="down" href="https://HOST/api/query?type=adminOrgVdc&amp;filter=org%3D%3D087a027e-f3c0-4fc8-8184-d1cc691ec254" type="application/vnd.vmware.vcloud.query.records+xml"/>
   ....

A few inaccuracies are also fixed (both have comments inline):

• There was duplicate call to setHttpUserAgent in request manipulation functions
• There was a missing logging for response function

[dataclouder]

Some minor issues in comments

[lvirbalas]

This is great!