refactor(web): refactor JS based keyboard related class and file names 🎼

[ermshiperete]

This PR renames several JS keyboard related classes and files to make it easier in upcoming changes to distinguish between JS and KMX based keyboards.

Part-of: #11293
@keymanapp-test-bot skip

[keymanapp-test-bot]

User Test Results

Test specification and instructions

User tests are not required

[jahorton]

My personal complaint here: in the long-term, the OSK should not need to be aware of whether the underlying keyboard is JS-based or LDML-based. There should be some common ancestor type between JSKeyboard and LDMLKeyboard (or similar) that provides the common properties that matter.

For example, the .isRTL flag would need to be available in some form for LDML keyboards, too.

• needed to correctly order banner suggestions + expand long ones on the correct side
• needed to select correct BKSP and ENTER key glyphs, which are directional

Keyboards will also have a name that's displayed to the user in some form, regardless of whether they're JS or LDML. (See TitleBar further below.)

[ermshiperete]

Completely agree. However, I'd prefer to do that in a later PR since it's unclear (at least to me) how that would be done with LDML. We can (and will have to) deal with it when we get there.

This PR is just one step further in my work with integrating LDML keyboards into Web and will require many more PRs and probably also changes to the changes that were made in this PR.