Initial Blazar support #2048

[micafer]

Add Initial Blazar support

Description

This PR adds initial support for the blazar service (#2048), listing the available leases and hosts.

Status

Replace this: describe the PR status. Examples:

• work in progress

Checklist (tick everything that applies)

• Code linting (required, can be done after the PR checks)
• Documentation
• Tests
• ICLA (required for bigger changes)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 96.34146% with 3 lines in your changes missing coverage. Please review.

Project coverage is 83.38%. Comparing base (9c0fb20) to head (43d1160).

Files with missing lines	Patch %	Lines
libcloud/test/compute/test_openstack.py	92.00%	0 Missing and 2 partials ⚠️
libcloud/compute/drivers/openstack.py	98.21%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##            trunk    #2049      +/-   ##
==========================================
+ Coverage   83.37%   83.38%   +0.01%     
==========================================
  Files         353      353              
  Lines       81650    81731      +81     
  Branches     8627     8632       +5     
==========================================
+ Hits        68068    68146      +78     
- Misses      10760    10761       +1     
- Partials     2822     2824       +2     

Files with missing lines	Coverage Δ
libcloud/test/common/test_openstack_identity.py	97.10% <100.00%> (ø)
libcloud/compute/drivers/openstack.py	85.48% <98.21%> (+0.49%)	⬆️
libcloud/test/compute/test_openstack.py	94.54% <92.00%> (-0.03%)	⬇️