Move tools to a plugin library

[JonasGilg]

This PR adds a new type of plugin called a plugin library. Plugin libraries are also located in the plugins folder, but are prefixed with csl, instead of csp.

• With the introduction of this feature the tools were moved from cs-core to csl-tools.
• To easily create plugin libraries a new PowerShell script was added: tools/New-PluginLibrary.ps1

I tested the loading of csl-tools with a copy of measurement tools on Windows. I did the following tests:

• Load both plugins and make sure csl-tools is loaded only once.
• Unload one plugin and make sure csl-tools is not unloaded for the other plugin.
• Unload both plugins and make sure csl-tools is also unloaded.
• Load both plugins again. A new instance of csl-tools was loaded.

To ensure that csl-tools was only loaded once, I logged the memory address of the logger.

Resolves #301

[coveralls]

Pull Request Test Coverage Report for Build 3273082836

• 0 of 16 (0.0%) changed or added relevant lines in 6 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.0004%) to 3.011%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
plugins/csp-measurement-tools/src/PathTool.cpp	0	1	0.0%
plugins/csl-tools/src/DeletableMark.cpp	0	2	0.0%
plugins/csl-tools/src/MultiPointTool.cpp	0	2	0.0%
plugins/csl-tools/src/Mark.cpp	0	3	0.0%
plugins/csl-tools/src/logger.cpp	0	3	0.0%
plugins/csp-measurement-tools/src/EllipseTool.cpp	0	5	0.0%
<!--	Total:	0	16	0.0%	-->

Totals
Change from base Build 3249311940:	-0.0004%
Covered Lines:	491
Relevant Lines:	16307

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💛 - Coveralls