change post_market_install to post_plugin_install

[TiTidom-RC]

Description

See discussion : https://community.jeedom.com/t/plugin-post-installation-hook/133020/8

This PR is only to change the name of the function from post_market_install to post_plugin_install, to take care of install from github too for example.

Suggested changelog entry

None as it only concerns devs of plugins => dev doc has to be updated with this new function.

Related issues/external references

None

Types of changes

• Bug fix (non-breaking change which fixes)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
  • This change is only breaking for integrators, not for external standards or end-users.
• Documentation improvement

PR checklist

• I have checked there is no other PR open for the same change.
• I have read the [La ligne directrice pour contribuer à ce projet / Contribution guidelines for this project).
• I grant the project the right to include and distribute the code under the GNU.
• I have added tests to cover my changes.
• I have verified that the code complies with the projects coding standards.
• [Required for new sniffs] I have added MD documentation for the sniff.