ARM builds of PMM Client

The problem: 

There is a lot of interest in ARM builds, but we cannot measure it for now. 
PMM Client looks like one of the projects where we can easily experiment and test ARM interest from the users. 

The goal: see and do some experiments to automate builds to be able to estimate in the proper future implementation of the ARM builds if needed 

 Note: PMM Client uses  PT inside, so w should also include  PT  ARM builds in this evaluation. 

Out of scope: 

• make ARM official and GA builds (for now, not in this POC)

Acceptance criteria (for future GA version):

• people can download packages and tarballs for arm systems 
• Percona can see statistics of downloads and usage and compare them with other supported platforms  

Reference:

• https://www.percona.com/blog/2020/08/04/compiling-a-percona-monitoring-and-management-v2-client-in-arm-architecture/
• https://mysqlonarm.github.io/Using-PMM-to-track-MySQL-on-ARM-statistics/
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