set min version compatibility for mv3 addons

[eviljeff]

We want to set a minimum version compatibility for add-ons that use manifest version 3, equal to the version of Firefox that supports it. (Need a target version of Firefox, or a guess for now - won't matter if it moves until we enable the submission switch)

@mixedpuppy want to estimate a target release? 98?

[eviljeff]

Going with Firefox 100 but we can change this closer to the launch (i.e. when the waffle switch is enabled)

[eviljeff]

QA: I'm not sure how testable this is on addons-dev this far in advance - Firefox 100 won't have been added as a version yet...? Interested to know what happens though!

[AlexandraMoga]

@eviljeff here are a few of the test scenarios I've tried on -dev (btw, new firefox versions can be added via the applications api)

• MV3 extension without compatibility set in the manifest => defaults to min 100.0 - max * in devhub manage versions page
• MV3 extension - with compatibility <100 set in the manifest => defaults to min 100.0 - max * in devhub manage versions page
• MV3 extension - with compatibility >100 set in the manifest => same compatibility threshold is displayed in devhub after submission - for example min 110.0 - max 110.* if this is what the manifest specifies
• MV2 extension without compatibility set in the manifest => defaults to min 48.0 - max * in devhub manage versions page
• MV2 extension with compatibility <100 set in the manifest => compatibility specified in the manifest is displayed in devhub after submission
• MV2 extension with compatibility >100 set in the manifest => same compatibility threshold is displayed in devhub after submission - for example min 110.0 - max 110.*
• MV3 language pack compatibility in manifest set to min 100.0 - max 100.* => compatibility specified in the manifest is displayed in devhub after submission
• MV3 language pack with compatibility <100 set in the manifest => defaults to min 100.0 - max 100.0 in devhub manage versions page
• MV2 language pack with compatibility <100 set in the manifest => compatibility specified in the manifest is displayed in devhub after submission

The results seem to be as expected.