Make beacons not apply effects when covered or base destroyed while using "allow-effects-with-tinted-glass"

[iamgabrieltv]

Resolves #1741 which reported unexpected beacon behavior while using tinted glass and "allow-effects-with-tinted-glass".

The problem with the base not updating was that with tinted glass being an opaque block it would still cause blockEntity.beamSections to be empty causing the below code to not check if the base of the beacon has changed.

if (!blockEntity.beamSections.isEmpty()) { 
    blockEntity.levels = updateBase(level, x, y, z);
}

The problem with the opaque block check failing above tinted glass was that isTintedGlass served as an override to the condition before applying the effects. To fix it I just set isTintedGlass to false if the block is opaque and not tinted glass.

[granny]

LGTM! Thanks for the PR :)